Hi Wendy -
I live in Bethesda (right up the road
) and bought my bike about four months ago. DC is a GREAT place to get started because there are great trails (which it seems like you are already discovering). I was really nervous starting out for a lot of reasons - I thought I would fall over, didn't really know how to shift, thought I looked silly, but I couldn't be happier now. Since it was cold outside when I got my bike, one thing that helped me a lot was doing some workouts on the trainer. It helped me get more comfortable, even though I wasn't moving. But, now it's so nice to ride outside, I could see how it would be painful to ride on the trainer.
I've also learned to avoid using my smallest chain ring (I have 3) because it messes up SO much (no matter how tuned it is). I know you said that your neighborhood has some hills, but most of the bike trails in the DC area are flat, so I find I never have to use it anyway. Mainly the fear of the chain falling off and having to stop are enough to keep me pushing if I ever come to a hill.
I'm sure you've found this website by now, but it's really useful.
http://www.bikewashington.org/
If you're up for a short road trip, the Baltimore and Annapolis trail is really nice for beginners. I went a few weeks ago on a really nice day, and it was virtually empty. When I started, I had anxiety about being on a trail with a lot of people (Capital Crescent near my apt. is unbelievably packed all the time), and this would have been the perfect one to start on - really nice trail, flat, and not a lot of people so you can really get to know your bike. But then again, I haven't been on the Old Dominion trail, so I don't know how the traffic is.
If you have any ?'s about my experience with DC trails, stores, etc., let me know. Happy biking!!
"It's a little like wrestling a gorilla. You don't quit when you're tired, you quit when the gorilla is tired."
-Robert Strauss