First of all I'd take the lump sum, and Calif pays it out in about 2.5 weeks. Usually, after taxes and the lump sum you wind up with about 1/3 of the jackpot. I believe they initially withhold 20% for taxes. There are no Calif. state taxes involved.
I would tell my GF first since she lives with me, and then my children. I would then buy a top of the line car like a Rolls, Bentley Mulsanne or MB Maybach. Next I would buy at least two homes. One in Rancho Santa Fe, CA, or some beach area, and one in Las Vegas. I'd live in Vegas from the start of the NFL season to the start of the NBA playoffs, or whenever the temperature hit 100 degrees. Then back to Calif. I'd go for the summer months.