I'll third the "dive in" comment. But make sure you have what you need. Will you be riding in the dark (get a white light for the front and flashing red for the rear)? In the rain (get some fenders)? Do you know the local road laws for bicycles (look them up online)?

Also, while you're debating cycling in, look at maps and test out new routes to work with your car. Pay attention to traffic levels, road width, hills, etc. Often the best bike route is not the best car route. My route takes me on mostly back farm roads, but it's worth it because I don't have to battle with angry commuters stuck in traffic.

Don't worry about your bike until you've been riding a while. You'll quickly learn what works for you and what doesn't.