I've loved bikes since I was a kid, but I've only been seriously riding for a little over a year. Here are some of the things that I've learned along the way.

-- You mentioned being worried about bumps in the road - this is a huge one for me, and it's taken me a while to get used to letting the bike do its thing. The bike really can deal with a lot more than you might think it can. You may want to practice riding on less-than-ideal road conditions in a controlled setting like a parking lot. Like, ride over a stick. Then ride over a bigger stick. You get the idea. Try grass, gravel, torn-up pavement, whatever you want to convince yourself the bike can handle. Of course in general on a road bike you don't want to seek out these conditions, but it's really helpful to know what some of the stuff that you might have to deal with on a commute (sand, dirt, uneven pavement, debris, etc.) feels like in preparation for when you encounter it for real.

-- Practice holding the bars as lightly as possible. Feel how you can steer just by shifting your weight, without needing your hands at all. If you rely too much on the bars for support or balance, it's tough to take one hand off to get a drink or signal a turn. Think about your core and feel how it's supporting you (ab exercises are your friends!). If you ever do spinning classes, that's a excellent place to play with this feeling because you're not afraid of falling, so you can move your weight around and start to understand what's happening with your balance. Once you're comfortable not relying so much on your hands for control and support, it'll be much easier to take a hand off the bar when necessary.

-- When you're trying to see what's behind you but still need to hold a straight line, don't think of it as looking over your shoulder, which I imagine as a sort of horizontal motion, but almost...through your shoulder, if that makes any sense. So don't swivel your head like an owl, but move it down and back. Drop your chin and then turn your head to the side, and then do that on the diagonal in a single motion - that diagonal is what you're going for. It's a small change, but it makes a huge difference because you don't have to fight the inclination to turn your shoulders. This is incredibly helpful when you're riding next to cars or other people since it makes it so much easier to hold a straight line, so I hope I'm describing it well enough!

-- Have you had a bike fit? Even if you had one when you got the bike, you may want to consider another with a really good fitter - if not now, than in a couple of months once you've had some time to get used to what your bike feels like and what you like and don't like - since sometimes the "bike fit included with purchase" variety isn't the best. There's nothing like a bike that feels GOOD for increasing your confidence!

-- Practice, of course! But you knew that. And don't pressure yourself - just keep pedaling, and you'll keep moving forward. I had a nasty bike accident (broken jaw, among other things) in the fall of 2008, I got a real road bike only a few months ago, and I just did the Harpoon B2B last weekend (150-mile 1-day ride!). Keep riding, and you'll be amazed at what you and your bike can do.