Any San francisco/California based freelance designers out there

Well, the plunge is about to be taken, and I'm going into the murky waters of freelance design full time. I have filed for sole proprietor status and I'm now official.

My question is, are there any professional freelancers from SF / California, that have any words of wisdom about setting up here (I'm from the UK originally) - tax implications, legal etc.

Not sure if this is the right place to post this, but any advice would be great. Feel free to PM me.

Cheers