The transfer fee is $15. You'll also have use taxes and smog certification fees on top of that. The California DMV has a web site that has all of that information and most of the forms that you'll need for the transaction. I think you'll find the answers to most, if not all of your questions at http://www.dmv.ca.gov/faq/faqbuysell.htm
The "use tax" is essentially equivilent to the sales tax on the fair market value of the car you traded. So figure around 8% of the kelly blue book and you should be close.