Everyone has a good time at Disneyland, regardless of age. It's just an awesome experience and your kids will have a great time.

Disneyland is broken up into different areas. Fantasyland is where alot of the rides for younger kids are. (Tea Cups, It's a Small World etc) There are no age restrictions but kids under 7 must have an adult on the rides with them. Alot of the rides don't have any height requirements either.

If you are not worried about them remembering the experience then I would do it. Definately.

Have fun!