Correct. You do not need a business license. Seller's permits are free, and most shows require them. You may show your resale licence when you are purchasing supplies for your business to not pay state sales taxes. Keep your receipts for tax time though.
You need to keep track of your sales. you have to pay taxes on ALL of your sales, unless they are from out of state. Even out of state sales must be reported, so make sure you are a good bookkeeper!
For more info, go here....
http://www.boe.ca.gov/info/reg.htm
hth...