For Legal information on homeschooling in the state of California:
Homeschool Association of California or
California Homeschool Network
(For legal information on homeschooling in other states, please see the HSLDA page.)
For Bay Area homeschooling resources, try the Homefires page.
For advice on homeschooling methods or curriculum you can either read the articles online at The Elijah Company (or order their print catalog), or go to the forums at The Homeschooler's Curriculum Swap.