Congrats on the job!
You will LOVE riding to work. It makes the day so much better!
If you're really scared about the commute, try doing a hybrid commute the first time. Maybe you can bring your bike to work one day, leave it at your desk/somewhere, catch a ride in with someone/the bus the next day, and ride the bike home. Or do the commute on a Saturday to nail down your route ahead of time.
I felt more confident once I had really scoped out my route (and my route is either 15 or 18 miles one way). Once you do it, you'll want to ride in more and more.
2007 Trek 5000
2009 Jamis Coda
1972 Schwinn Suburban
"I rejoice every time I see a woman ride by on a bike. It gives her a feeling of self-reliance and independence the moment she takes her seat; and away she goes, the picture of untrammelled womanhood."
Susan B. Anthony, 1896