The key to a successful kid joke for the younger crowd is keep it simple.

This is an important (but often overlooked) point for an aspiring young comedian, anything that requires too long of a build-up can easily flummox, so short and sweet is generally the best bet.

It's also a hit if the child has a joke that fits the occasion. My kids' best Halloween was the year they dressed up as skunks and had this little gem to share with the people who passed out candy:

How do you keep a skunk from smelling? Hold its nose!