The best advice I can give you is:
1) http://www.chameleonforums.com/
2) They aren't cheap, but they aren't as difficult to get to thrive in captivity as some sources claim.
3) The most important diet advice I have is variety is good.
4) Don't get your heart set on a veiled right away just because it's the first chameleon your son held. I highly recommend panther chameleons as well.. their colors are out of this world.