There are two main Companies near Anaheim and the rest of the Southland.
The first is near Lake Elsinore and the Cleveland National Forest, and the other is in Perris Valley. They are both in Riverside County, which is basically east of the Orange County/Los Angeles County area.
http://www.skydiveelsinore.com/
They offer a "First Jump" course, which is NOT a tandem jump, but two instructors jump with you, and you have a special rig with a special reserve chute in case you pass out (designed to deploy at a certain height if you are going too fast). Plan for about 8 hours, starting with a 6 hour class early in the day. Nearby is a lot of shopping, including and outlet store, and even the Pechanga Indian casino, which will allow you something to do after dropping him off, and be back in time to see the actual jump.
The other is a bit further away in Perris Valley.
http://www.skydiveperris.com/
Once again, the same type of Free Fall as in Lake Elsinore, but Perris Valley has an indoor simulator as part of the class prior to the actual jump.
Price are about the same, alas, there is less to do in the Perris Valley area, so that might be a factor.
But we are looking at about a 2 hour drive to either locations from Anaheim.