Congratulations! I hope everything goes off next week with a hitch!
Griffith Park and Observatory is a beautiful park with a family friendly science museum. The Hollywood sign is also on the same ridge. A lot of movies have used the observatory -- Terminator 2 and The Rocketeer for example. Great views of the city, interesting architecture and Free!
I agree with Mouserocks on Magic Mountain. Knotts Berry Farm (another amusement park) is also a lot of fun. I highly recommend the boysenberry pie.
My experience with Hollywood is that it's interesting but I'd advise you not to stay late. Unless things have changed in the last few years, you don't want to be around the crowd that comes out late at night.
In-n-Out is good and I'm still waiting for an el Pollo Loco franchise in Michigan. Unless you're hungry for pizza it doesn't seem like there are a lot of mom and pop Italian restaurants out there.
On paper Los Angeles and Anaheim are different cities--in practice it's all one city and you'll probably never notice where one ends and the next begins. Plan on using surface streets only to get to and from the freeways. Otherwise you'll spend way too much time sitting in the car stopped at traffic lights.
