I think LEGOLAND is easily the best theme park in Southern California for kids 3-10.  Why?  The crowds are not nearly as large as Disneyland, Universal Studios and the like.  There is more for the kids to do.  It is flat out funner and more educational than any of the other theme parks in the area.

This is not a guide about what rides to hit up.  Rather, these are hard learned rules about making your visit really pleasant and insanity-free.  Here we go, in no particular order.

1. When driving from Los Angeles, there is a viewpoint several miles past San Clemente. Besides the fantastic view of the ocean, you’ll find that a huge family of squirrels lives right off the cliff.  They love crackers and take them right from people’s hands.  Bring some, the kids will love feeding them furry creatures.
   
2. If you are going to let your kids do face painting, do it after visiting the Pirates section (e.g. all water attractions).  Yes, learned the hard way.
   
3. Bring a bathing suit, seriously.  LEGOLAND has several water rides and your kids are likely to get soaked head to toe. 
   
4. To that end, park a small backpack on yourself.  This way you can carry all the stuff (bathing suits, possibly a towel, food the kids haven’t finished, etc…).  Make sure it has a small rubberized mesh pocket on the side (most do).  Why?  Go to next point.
   
5. Before you get to the water rides, you are likely to see The Garden Restaurant.  It’s by the entrance to Miniland.  If you get a combo there, you’ll get a drink in a nice and tight plastic container.  They have fountain drinks.  So you can get free refills all day there.  It’s central location makes it convenient.  Well, actually I don’t know if they allow free refills.  That is what I did and no one said anything.  Anyway, the deal with the rubberized mesh pockets on the backpack is that they are perfect for the drink containers.
   
6. When should u go?  Let’s start with when not to go: Saturday during the summer vacation.  This is kind of a no-brainer.  My favorite time to go is during the school year, when the school is having a day off due to a teacher conferences.  There are at least 2 or 3 each year.  Imagine spending no more than 4 or 5 minutes in line (worst case scenario) on ANY ride.
   
7. The food in the park is expensive, no doubt about it.  And the kids will surely get hungry, also no doubt about it.   So if you are planning to be in the park from 11 to 8, you need to plan it out so that the food cost doesn’t actually exceed the cost of the ticket.  So before getting to the park, stop at some restaurant and have a good meal.  Then have one filling meal inside the park and finish up with another one after getting out of the park.
   
8. If you are the type that brings food, you will likely have to leave the park and walk all the way back to the parking lot to your vehicle.  Try and setup the day, so that you only have to do it once, because it is quite a long haul.  Meanwhile, bring some snacks with you into the park (that’s where the backpack comes in) to tide the kids over till the trip to the parking lot.
   
9. Suntan lotion.  Bring it.  Summer or winter.
   
10. Height restrictions.  The park has various height restrictions for various rides.  If you have small kids, it is very likely that either you or an older sibling will have to ride with a younger one.  That is why it is advisable to have an even number of people in your party.  Believe me when I tell you that it is NO FUN to have go on a ride, that does nothing but go around, with each kid separately.