Another MUST, IMO is to buy a copy of Henry Kingman's great little book "Short Bike Rides In And Around San Francisco". It is full of interesting rides to help you get familiarized with the city, but also with many tips and routes for getting around in the city via bicycle. So it's useful for commuters as well as for those riding just for pleasure or to see the sights. I actually have two copies because I lost one for a while (I'm a disorganized slob) and couldn't be without it. The most recent edition is the 2nd Edition, and it's several years old, but still very very valid and useful.

You can get it on Amazon http://www.amazon.com/Short-Bike-Rid.../dp/0762702141