nhluhr

Sure thing:
The major "club" around here is the Cascade Bicycle Club http://www.cascade.org/Home/ They are the primary clearing house for bicycle activism, organized group rides, major organized charity/event rides, etc. If you get on their mailing list, they send you things like how to vote to benefit cycling infrastructure, reminders about upcoming big century rides/etc.

Some of the iconic event rides are:
Chilly Hilly - Early season opener (Feb) on Bainbridge Island. Take the ferry from Seattle and ride the routes
Apple Century - 2hr drive from Seattle out in the apple growing areas of Wenatchee and Leavenworth WA. Super-scenic and way better than the other event ride options that weekend.
7Hills of Kirkland - nice route that hits 7 of the notable climbs in close to Kirkland.
STP - Seattle To Portland (took place this past weekend). 204 miles, done in 1 or 2 days, 10,000 rider limit with tickets selling out in February with CBC members getting first crack.
RAMROD - Ride Around Mount Rainier in One Day - 154miles, 10,000ft elevation gain over basically 2 major climbs and several lesser ones. 800 Rider Limit due to National Park rules, done in a lottery. Many groups do it in smaller private events on other weekends without the hassle of the Redmond Cycling Club's lottery system
High Pass Challenge - 114mi, 7500ft climbing, in/around Mount Saint Helens
Kitsap Color Classic - Late September ride on Kitsap Peninsula. Take the ferry from Seattle and ride the various length routes

Local Racing Season:
Most of the racing is handled by the Washington State Bicycle Association ( http://www.wsbaracing.org/ ) and are USAC sanctioned. You'll need your USAC license and also a WSBA number for them. The event calendar is here: http://www.wsbaracing.org/calendar.html but can also be added as a shared calendar to your own Google Calendar view. Season opens with road racing typified by 10-20mi loops repeated as appropriate for category. It then transitions into a period of 3-event stage races in various locations like WallaWalla, Enumclaw, and Olympia. Then you have a month or two of primarily Criterium races, finally closing the season with a series of circuit races (6mi loops, repeated as necessary). Throughout all this, you have weekly Tuesday racing on a nearby motor speedway in Kent (Pacific Raceways) and weekly Thursday crits at Seward Park in Seattle. These weekly races are not USAC so no upgrade points, just glory. Mixed in are various events like the Ronde Van Palouse (6mi of gravel per 16mi lap), a few Kermesse races, etc.

Local Racing Teams:
There are a TON of teams in Seattle. I won't describe each for fear of sounding biased, I'll just list as many as I can think of... I also don't know the actual team name but certainly the title sponsors of most:
Garage Racing, Cucina Fresca, Lake Washington Velo/HagensBerman, Union Bay Cycling/bikesale-ViaMotors, Apex/CycleU, KellerRohrbach, RecycledCycles, SecondAscent, JL Velo, Harriot Sports Performance, KrykiSports/Audi, Peterson Spokeswomen, etc. Also many teams in nearby areas like Tacoma, Portland, Olympia, Spokane, etc.

Major Rail-Trails/MUPS:
Burke-Gilman Trail - Starts at the west half of Seattle and roughly follows the ship canal through lake union before heading north towards Bothell along Lake Washington's NW shores. It feeds seamlessly into the Sammamish River Trail and is VERY heavily used by commuters and recreationists alike. Major improvements slated for the portions around UW in the coming years. Along the way, this MUP passes iconic Seattle places such as Gas Works Park, Magnuson Park, UW, etc.
Sammamish River Trail - Starting at the end of the Burke-Gilman in Bothell, it continues around past the Redhook Brewery all the way to Marymoor Park in Redmond. There is a velodrome in Marymoor Park with regular track racing classes and series. It's open to the public when not being used by events. Many of CBC's group rides start at Marymoor Park.
Green River Trail - don't be afraid, no serial killers here for a long time. Starts down by Boeing Field and continues all the way to Kent, along the Duwamish and Green Rivers. For a long time, it was blockaded with giant sandbags because the Army Corps of Engineers though an upstream dam would fail. The sandbags are removed and the trail continues to be improved by the cities it goes through.
Interurban Trail - discontinuous north-south trail that exists both south and north of the city to help get between urban areas. It's generally very straight but has a lot of road crossings.
Cedar River Trail - Starts in downtown Renton and goes SE toward Black Diamond along a gentle grade.
East Lake Sammamish Trail - Goes from Issaquah to Redmond along the east side of Lake Sammamish. Just finished paving. I personally just ride the wide, bike-laned shoulder of East Lake Samammish Pkwy. Feeds pretty seamlessly into Marymoor Park and thus can connect easily to Sammamish River Trail and Burke Gilman Trail making for 40miles of almost continuous paved MUP.
There are other trails to the east but I don't know them as well since I tend to just stick to roads out there. One notable unpaved trail is the John Wayne Pioneer Trail (aka Iron Horse State Park). The trail starts at Rattlesnake Lake near North Bend and follows a 1-2% railroad grade all the way up to Snoqualmie Pass where you then ride through a 2.3mi tunnel in total darkness, before continuing the rest of the way. In total, the JWPT is 300miles long and goes from Rattlesnake Lake to the Idaho border. Sections past Yakima are not yet developed though. The bit from Rattlesnake Lake to Snoqualmie Pass is 21mi and about 1600ft elevation gain. Really fun if you have a bike capable of handling this sort of trail (mostly packed doubletrack with sections of rough gravel - recommend at least 28s with reinforced sidewalls, preferably 32+ with knobbies like a CX bike).

Notable climbs in the area:
Juanita - from Kenmore or from Kirkland. Goes from around 30ft up to around 450ft. Kenmore side is steeper.
Norway - from Bothell/Riverside Dr. Goes from about 40ft up to around 470ft.
Hollywood - From Woodinville Tourist District. Goes from about 50ft up to around 550ft. Clockwise is steeper.
Perkins - From Lake Forest Park. Goes from 40ft up to around 440. A little less elevation gained allows you a terrific low-stress hill repeat loop up 178thSt/24thAve with safe lower angle descent down Perkins.
70th St NE- From Magnuson Park. Goes from about 60 up to 400 via straight-up-city-blocks. Rough pavement, really crappy descent. Repeat loops should be descended via another route.
On the east side (the east side of Lake Washington), there are plenty more climbs of this magnitude but a few of particular note like Novelty Hill in Redmond and most importantly, Zoo Hill in Issaquah. Zoo Hill is easily accessed as part of a moderate length ride from Seattle and has the distinction of being the biggest climb you can do here without having to drive somewhere. From Newport Way on the west side of Issaquah, ride up SE 54th St at the sign for the Cougar Mountain Zoo. It's fairly steep. Stay on this through some switchbacks and finally the road turns right into a long straight that appears to be rolling but it's really just rolling back and forth between uphill and steeply uphill. Once you reach the top of this straight section, turn sharply left up the hill and continue, looking for a "Private Road" to the right that heads up to the radio towers. This goes from 100ft to 1450ft in under 2.8 miles, average grade 8%, several bits at 15%, one bit at 20%.

Suggested Ride Loops:
3 Hills - Start maybe somewhere in Kenmore and ride out to Woodinville, hitting Hollywood, then returning via Norway and Juanita.
Lake Washington - About 52miles total, mostly safe surface streets, go either direction but clockwise is probably easiest to minimize left turns.
South End - Lake Washington Loop, southern half only, cut short with a transit across I-90 bridge(bike path) and Mercer Island
North End - Lake Washington Loop, northern half only, cut short like above.
Mercer Island - No matter how you get here, riding the loop around Mercer Island (West Mercer Way and East Mercer Way) is terrific. No stoplights for about 15mi and it's all rolling and twisty with safe vehicle traffic. I prefer counterclockwise to make the twisties on the east side of the island just barely downgrade (and thus faster).
Snohomish Loop - Lots of different ways to do this, but basically start from Bothell and head north toward Monroe and Snohomish, hitting a lot of country roads along the way.
May Valley - Whether you make this part of a loop linking Lake Washington to Issaquah or Renton, or if you use it to link down to the Cedar River Trail, it's a great road to link up some nice loops. Mostly flat or false-flat but it gets you there.
Zoo hill and the lakes - You can start in Seattle, head across I-90 or around the south end of LakeWash, then up Newport Way to hit ZooHill, then down lakemont and around the east side of Lake Sammamish, through Marymoor to choose your own adventure back to Seattle - long flat way around the SammRiverTrail or up over Old Redmond Way into Kirkland to link up toward Juanita back into Kenmore before heading south via surface streets or Burke Gilman Trail.

Notable climbs within a reasonable drive:
Hurricane Ridge (Olympic National Park) 0 to 5400'. This is just about exactly one half of haleakala, starting from sea level in Port Angeles and heading straight up to the top of the park. 17 miles, 5400ft gain, same gradient as Haleakala - 5.3%. Usually open but not accessible by bicycle in winter.
Ashford to Paradise (Mount Rainier National Park) 1800 to 5450'. Open in winter, but no bikes once it snows. Snowpack at Paradise reaches about 200 inches depth by spring.
Greenwater to Sunrise (Mount Rainier National Park) 1800 to 6400' - starts out low angle 1% but steadily gains then ramps up once you enter the Park. Drop down about 200ft to the White River before the main portion of the climb to Sunrise. This road is only open between the last season of June and until the first snows render it unsafe from avalanche or lack of plowing.
Cayuse Pass - From either side, it's a good climb. I like it from the south at 2200ft on up to 4700ft. Most people experience this as part of RAMROD so they start this 5% sustained climb after they've already pedaled 100mi. Closed in winter.
Chinook Pass - Usually done as a piggyback on a Cayuse Pass ascent. It starts at the TOP of cayuse and continues up on hwy410 to 5400ft in a couple more miles. Closed in winter.
Mission Ridge - Starting from the sunny dry side of the mountains in Wenatchee at 750ft, heads up a valley toward the Mission Ridge ski resort at 4400ft. Very light traffic for the most part. Terrific pavement with switchbacks at the top and a sustained gradient of 6%, with the top half being almost all greater than 8%. Terrific climb.
There are a lot more that a guy named "Seattle Forrest" posts about in the Pacific NW forums such as Blewett Pass, the North Cascades Highway, and Mount Baker. He posts nice photos and details of the climbs too.

I hope that's not too much information but the cycling 'scene' here is really extensive. Yes, it gets cold but rarely below freezing and yes it rains a LOT from about October to May but most of us just learn to deal with it for love of riding. Things like glove/boot dryers, packable rain vests/jackets, shoe-covers, etc make it livable. From July through September, you can count on almost 0 rain and mostly sunny skies every day. Also, something you won't be used to - variable length days. In the winter, daylight may get as short as 8hrs (sunset at 4:30pm) and in the summer, you get up to 16hrs (sunset after 9pm). How you learn to deal with that will greatly affect your enjoyment of the region.