All About Birds - official site of the Cornell Lab of Ornithology. Great online field guide and audio guide, plus lots of other fun bird-related stuff!
Bird Links - large list of bird related links, both national and specific to CA, by City College of San Francisco professor Joseph Morlan.
BirdSource - Cornell Univesity webiste with online field guide, birding feeding tips, tricky ID's, birding tools, and more! Plus info on the Great Backyard Bird Count.
CA Audubon - info on our CA native bird species, birding, research, and citizen science.
Golden Gate Raptor Observatory - Located just north of the San Francisco, this sites has info on CA raptor migration, volunteering, docent programs, and research.
The Owl Pages - everything owl! From species info and physiology, to culture and tattoos!
The Peregrine Fund - information, images, and resources about raptors