Polypro it is the best thing invented since sliced bread. Fenders yes, rain suit yes (I have 2 a heavier one for winter and a lighter one for spring ) We have the largest and most active bike club in America here Cascade Bike Club there is also for your MTB there is the Back Country Bicycle Trails Club There are some really awesome rides here and there are a few of us on the Forums thta woul be more than willing to show you around. This area is prime for both road and mountain biking give as a call when you get here

(and a flock of really good brew pubs if you like that sort of thing)