I like San Francisco Cyclery on Stanyan.

SF cyclery

When my friends and I were looking into getting into biking last Fall, they were the only shop who took the time to talk with us, and listened to what we were willing to spend, and were very nice and patient. I took another bike there to be worked on, and the service has always been great.

It's not super close to SFSU (but it would be a nice ride to get there). There are a few shops closer to SFSU(off of the top of my head, one on Ocean and one on taraval).

edit:

here is a review on them. I dunno what is with the middle review. But the top review is spot on with my experience there.

http://www.yelp.com/biz/4ZtmVkdtfS3LT2S1d_KZhA