Do to the rise in gas prices I'm seriously considering riding to work since it's only a few miles away but had a few questions -

1. What brand of bike would best suit my needs?

2. How much wear and tear is put on a bike when ridden in the rain?

3. And is there anything else I should be aware of?

The rain puts some wear on your drive train. Some of your parts will wear down sooner than they would on dry, sandless roads. You'll go through chains a little sooner, which cost $10 to $50 to replace, depending how fancy you go, and cassettes, too, which might run you $20 to $100. The chain rings wear very slowly.

How far do you live from work?

2.5 miles

Don't worry about parts wearing out on a 2.5 miler. I'm doing a 34 mile round tripper myself. Definitely commute. It will be the best part of day.

For only 2.5 miles you can ride just about any type of bike. Of course, once you start doing it, you'll want to ride farther, and farther.. so keep that in mind when you are bike shopping..

2.5 miles is a pretty easy commute. Keep your chain lubed properly to prevent rust and you'll be fine for a good while.

Awesome! Now when it comes to rain gear (jacket, pants, backpack) are there any specific brands you guys recommend?

1 Instead of brand, focus on the type of bike to get.
A roadbike may not have the ability to mount a rear rack
and/or fenders. A downhill mountain bike may be real
beefy for jumps, but those suspension bits may just weight
you down and minimize your pedal efficiency.

2 Increased wear and tear riding in the rain and snow won't be
so great. In othe words, it's not like you'll wear out your rims
twice as fast.

3 Your 1st bike may not be your last. After your first purchase
and you had a chance to experience bike commuting, you may
want to change your ride or modify it more.

brand means nothing. Its ford, chevy, porsche. They all have good and bad, top models and bottom ones. They all make sport utilities and sports cars.
What style is the question you should be asking. Thats depends on if you need to carry stuff, how much you need to carry and how you want to carry it.

2.5 miles is a short ride. Old mountain bike with slicks would be the cheap entry level to see if you like it. Personally I would recommend a better name like Trek, Cannondale, Specialized, Jamis. If it has a "Ashtbula crank" and made in the last 20 years it is typically the sing of a low end HEAVY bike. Proably the most common bike you could look for used that would make a decent commuter would be something like a Trek 820. $80 usually will buy a good one.
Suspension on the road is typically just extra weight and rear suspension tends to waste effort better used for forward motion.

Take a look at this thread and you will see budget commuters made out of Rigid mountain bikes.
https://www.bikeforums.net/showthread...r-Bicycle-Pics

Thirft stores, Salvation army, Goodwill for rain jackets, pants and bags

How hilly?

I wore out a chain on my road bike a few weeks ago. It took 2,000 rainy Seattle miles. Mine was a 10-speed chain; if I'd had fewer gears ( in the back ) it would have lasted longer, and cost less to replace. So mine is the worst case scenario for you, and would get you 400 round trips to and from work.

Just wear whatever clothes you're comfortable in, unless you need to climb a mountain on the way in. And get whatever bike fits you and feels natural.

Can you store it indoors at work?

It's not hilly at all. There aren't too many hills in Missouri unless you're down in the Ozarks and I'm not.

And they would prefer I chain it up outside.

The biggest issue is to make sure whatever bicycle you select, that it fits you properly.

Here are some pics that commuters in this forum ride on:
https://www.bikeforums.net/showthread...r-Bicycle-Pics

That probably rules out really expensive carbon fiber bikes. Otherwise, use whatever you like. For a very short, not too hilly ride, you don't need "cycling" clothes, or anything out of the ordinary. And you don't need steep hill gearing, etc. Chances are you won't need to carry much with you, so you don't need a bike with lots of cargo capacity or anything.

Can you get away with leaving your bike lock at work, locked to whatever you'll lock your bike to in the day?

I was in Springfield, MO for a while and used my bike as primary transportation around 9 years ago. It's not very hilly in that area, and I just rode a mountain bike around. If you already have access to a bike it would be a good idea to use that + backpack first, then decide if you want something else. At that point you would have a better idea of what you're looking for. I've since moved to a cyclocross bike with a rack and fender and use a pannier to transport my stuff with me. Your needs might be different than mine, though.

For this issue, you may want to consider a folding bike that can be bagged up and carried inside unseen.

It's 2.5 miles. Don't overcomplicate it. Go to a thrift store and buy the first bike that fits or borrow one from a friend or relative. Oil the chain and fill up the tires and go. Wear a backpack if you need to carry stuff. If it rains, drive your car.

After a month, you'll know whether you like it enough to invest in better equipment.

^^^ what he said.

2.5 miles, not hilly, you should ride in style on an old Schwinn cruiser with a big old front basket. Or rear basket. Or, preferably, both.

2.5 miles is walkable. That being said:

-Establish a budget. Don't blow it all on the bike, you'll need some essentials for your commute. Lights, lock(s), flat kit.
-Find a LBS that you like, then take a look at what they have. Listen to what they have to say.
-What you wear and how you haul your stuff will be a trial and error thing.

Those work but I went a little upscale by raiding a discount department store for rain pants and got a windproof and waterproof jacket from a work wear store. For bags I use panniers but I have to drag along clothes and books to and from work.

If you're going to leave it outside, I'd go with something cheap and relatively theft-proof. Check out thrift stores, Craigslist, and yard sales - sealed bearings might be nice.

Just go for it! The benefits are wonderful, numerous, and sometimes unexpected!

I plan to ride in the rain.

Then you'll want a bike that can have fenders installed, and will need a waterproof backpack or pannier to carry stuff.

Don't let the rise in gas prices be the main reason. That indirectly says, you would still rather drive, than commute by bike.