Use Google to check the tax rates when you visit since you'll be here after the first of the year. Tax rates can change then, so double check before you arrive. And tax rates in L.A. County are higher than in Orange County, so if you'll be dining and shopping in L.A., check again. (Google makes this so easy!) And (more fun!) certain cities have their own tax rate, so it can't hurt to double check if you leave Anaheim. Welcome to the circus that is CA!

ETA: Really, this isn't super complicated, but I know you like details, so I included them.