There are literally hundreds of things to do here in LA. Here is my list of “must sees”. Visit as many as you have time for.:

Disneyland: The Happiest Place on Earth. Half a billion visitors can’t be wrong. #1 Destination.
Universal Studios: A theme park that grew out of a studio tour. #2 Destination.
Even if you don’t visit Disneyland or Universal Studios Tour, Downtown Disney District and Universal City Walk are very fun places to visit for shopping and eating. And they’re free to visit.

Hollywood: Hollywood Boulevard is ready for its close-up, thanks to years of urban renewal and renovation. Most kids won’t really like the Walk of Fame or Chinese Theater. However, the El Capitan theater, which was restored to its former glory, is owned by Disney and shows recently released Disney movies as well as older Disney that has been released on DVD (like the Little Mermaid).

Olvera Street/Union Station: Olvera Street is the birthplace of LA, and it emphasizes our Mexican heritage. In addition to the Avila Adobe (oldest building in LA), you can eat at some pretty good Mexican Restaurants, do a little shopping, and taste a churro. If you don’t want to go to Tijuana, this is as close as it gets without going there. Union Station has great architecture from a bygone age. Also, you are 2 blocks from Phillippe’s (see below).

Santa Monica Beach and Pier: Great beach scene and a classic seaside amusement park, complete with antique carousel that has been in a lot of TV and movies. (The Sting and "Three’s Company" come immediately to mind).Bubba Gump Shrimp Company right on the pier. Kids love the rides on the pier, and the games. Or just playing in the sand.

Griffith Park – Home of the Los Angeles Zoo, Griffith Park Observatory, Travel Town, the Greek Theatre, Pony Rides and Griffith Park Railroad, Merry-Go-Round, and Gene Autry Museum of Western Heritage. While the zoo is not as good as San Diego Zoo, it is still good, and enough to entertain most kids. The Pony Rides and railroad are for the younger kids. Travel Town is a rail museum where you’re not SUPPOSED to climb on the engines, but kids have been ignoring those signs for 40 years. The recently renovated Observatory is a lot of fun. Or you can just play in one of the picnic areas in the park. There are plenty of toys to play on.

Los Angeles Science Center: A favorite museum for kids for over 40 years. Exposition Park, by the Coliseum.

Discovery Science Center, Santa Ana: The big cube right next to I-5, exit Main St.

Los Angeles Children’s Museum: Located in the Hansen Dam Recreation Area, currently under construction. Original location near the Music Center is closed.

La Brea Tar Pits/Paige Museum: What kid doesn’t like dinosaur exhibits?

Aquarium of the Pacific, Long Beach: Lots of fun marine exhibits for kids to explore. And the mac and cheese at Bubba Gump’s across the street is good, too.

Legoland, Carlsbad: This is more of a San Diego attraction, but kids 10 and under generally love it.

Places to eat:
In-N-Out Burger: Multiple locations, best burger in LA, ask anyone.
Pink’s Hot Dogs: 709 N. La Brea, just north of Melrose. Might see a celebrity.
Tommy’s Chili Burgers: Look for the shack, an LA tradition. Original location at Beverly & Rampart, a couple miles west of downtown.
Canter’s Deli: 419 N. Fairfax, between Beverly & Melrose. Near CBS, might spot a celebrity.
Phillippe’s: 1001 N. Alameda. Great roast beef sandwiches. Near Union Station, Olvera Street. Watch the mustard, it’s hot.
Cap’n Kidd’s, across from Disneyland: NOT!

Lot’s of options in L.A. Here are a few more ideas.

If you’re into museums, the Getty Center and the Getty Malibu are great options. http://www.getty.edu/

There’s also the Gene Autry Western Heritage Museum, which has some nice displays of western paraphernalia, including a collection of guns, and has the additional advantage of being right across from the LA Zoo. http://www.autrynationalcenter.org/ http://www.lazoo.org/

There’s the Long Beach Aquarium: http://www.aquariumofpacific.org/
And the Cabrillo Beach museum and aquarium: http://www.cabrillomarineaquarium.org/

Good food: well, if you want to try something different, you might want to go to one of the area farmer’s markets, which all have vendors serving things like Thai food, Tamales, Peruvian chicken, apple skivers, all kinds of good stuff. http://www01.smgov.net/farmers_market/ (And these markets are chock-a-block full of some of the best tastiest peaches, cherries, nectarines, melons and other summer fruits you ever tasted!)

Hope that helps.