There's an interesting website:

www.nrdb.org

where records are kept of all flora/fauna seen in the various preserves / parks / open space areas in the SF bay area. It includes much more than birds, but it certainly contains birds, and if you're interested in seeing what you might find if you go to, say, Big Basin, it'll generate a check list for you. Also, if you spot something new, you can submit a report to have it added.

The "nrdb" stands for "Natural Resources Data Base".