I started commuting in Dec 08, so I'm still figuring some stuff out, but here's my commute:

I ride 5.5 miles from my house to the park and ride station (about 20 min). This stretch is mostly rolling hills, so I never get a chance to build up much speed. From the park and ride, I take the bus to downtown (about 20-30 min) and get off the bus on the opposite side of campus from my work. I then ride 1.4 miles across campus to work.

Overall it takes me about an hour. If I didn't ride the bus it would be a 23 mile ride one way. I haven't worked up the courage to try that yet.

I ride a 2006 Kona Lana'i with a 1.75 Vittoria Randonneur on the front and a 1.95 Kenda K-shield on the back. Definitely not slicks, but much less rolling resistance than knobbies. I have added a rack to it and carry my work clothes and bike tools in a Novarra rack trunk. I would like to get either panniers or a slightly bigger rack trunk, but what i have now works, so I'll wait to change it.