California Master Gardener Handbook
The UC Davis cooperative extension office is now publishing the California Master Gardener Handbook, an incredible reference for those of us gardening here in the Bay Area and elsewhere in California. Similar in concept to the old favorite Western Garden Book, this is a 700-page ox-walloper of a book, customized for California's many climate zones and soil types.
If you're unfamiliar with the Master Gardeners program, this is a good time to start learning about it. It's a county-by-county service that helps identify and train community members who volunteer and work locally to spread gardening knowledge. Santa Clara has a very active chapter, which does demonstration gardens in Prusch Park in San Jose, and up in Palo Alto and other areas as well.