Heres an answer from my 15 yr old snare drummer:
Ok: here we go. first off, i know everyone loves the movie drumline, including me, but in real life, those types of bands that are in that movie are very very hard to find. But they do exist. but unfortunitly, there arent any types of books that teach the same exact things that they do in those bands. but there are a bunch of things from an organization called drum corps international, or dci, that could help a whole lot. There is a vic firth website that has a lot of videos that are from dci this past summer. and they show a lot of flashy stuff, which is probably what he is loking for. just go to these sites:
www.vicfirth.com and click on the dci link
www.innovatinepercussion.com and click on the dci link
youtube and search- blast! battery battle. (that is part of an indoor show that shows the best of the best percussionists)
and also, when your at vicfirth.com, look for a tab at the top that says features. after youve clicked on that, click on marching percussion. a bunch of pictures and links of people should show up. and you can click on any of those and see some cool stuff. but i would reccomend watching jeff queen. he gives actual lessons on the site and your son could learn a lot.
and for some cool videos on youtube, search:
2002 or 2003 electric wheelchair. (make sure the description says santa clara vanguard, or scv.)
drumline diddy- by the blue devils
and you can type in the name of some corps also like, the caveliers, the cadets, phantom regiment, spirit of jsu, blue coats, or others.
Thats his advice, hope it helps and good luck!
Ps , he says its lots of fun