Ok - here's the real deal for California in 8 easy steps.
1. Find a place for your brewery. It can't be in a residence or an attached garage.
2. Contact your local planning department and convince them that your brewery is not a zoning violation. Offer to voluntrailly limit your production if they give you a hard time. Beg if you have to. This is the biggest obstacle.
3. Go to the Cal. ABC and apply for a type 23 "Small Beer Manufacturer" license. It allows you to commercially brew up to 80,000 bbl a year. I takes about 45 - 60 days and will cost you about $450 with the first year's fee. After that its about $150 a year. You have to meet with them and they'll give you a sign for your window. Hope no one in your neighborhood sees it and if they see it they don't file an objection.
4. Apply to file a Brewer's notice with the TTB. This is more of a pain than everything else. You will need to post a tax bond of about $1,000. You can either post cash or get a bond issued on collateral. They've got a list of places that issue bonds. This takes about 45-60 days.
5. Apply to the Cal excise tax board and to pay.gov to open excise tax accounts.
6. Learn the COLA system and how to get label approval.
7. Wait for stuff in the mail.
8. Brew beer and live hapily ever after rolling on a big pile of money with many many beautiful women.
A few other tidbits: You don't need FDA approval or inspection, although your brewery is subject to inspection by the CA ABC or the TTB. If you brew with anything other than malted grains (wheat, rye, and the normal stuff are included), yeast, water and hops you'll have to submit your recipe for approval (ie. chocolate stout, etc). You'll have to figure out a way to separate "tax paid" beer from pre-tax beer. You can only give away beer under specific circumstances. The fire department may want to review your rig and brewery premises.
There's more stuff but I can't remember at the moment.
...yeah...I passed the bar...and this post is probably the most useful thing I've done with it...
Gordie