What inspired me? Being stuck in traffic watching people fly by me on their bikes.
Also, getting 40 miles in on one day without spending any extra time is a huge bonus! (Drive + gym time is more than bicycle commute). For not being a morning person, I really love being out on my bike early in the morning. Everything is fresh, cool, beautiful, and not much traffic at the time I leave.
The thing that helped me the most to get started was that a co-worker who lives near me and commutes regularly offered to ride home with me to show me the route. The city I work in is, while very bike friendly, very congested, particularly the area right near work. It happens to be a half mile from a huge university, so there are lots of bike paths to help. I looked at the bike path maps, and then took it one step further and looked them up on Google maps with the satellite images. This really helps when planning alternate routes, I can see the bike paths and bridges and underpasses on the satellite images.
Finally, I would tell myself (and still do), if worse comes to worse, I can just pull over and stop. Either because I missed a turn and I need to go back, or because I can't get through traffic to make a turn, etc. No one is watching me to see how I do, and there are no point deductions for making mistakes. I can just stop, get my wits about me, then carry on.
Have fun, you will love it! Let us know how it goes.
The best part about going up hills is riding back down!