Keller Williams Estates Calabasas
Since most properties under $250K around the Bay Area are being picked up by cash buyers, you would have to look around the central valley, perhaps Modesto, Stockton, etc. Even Sacramento is getting tough at that budget. In any case, you're still investing in properties that harder to manage, which is not a good idea for a first-time investor.
$100K doesn't buy much in CA....but perhaps you can go to areas that were once booming with new properties, have since become foreclosure capitals, but are on the comeback trail. Check out Stockton, Pittsburg and Antioch