Just some hints. Don't try to memorize dozens of hand signals. Just pick a few pieces of critical info to relay in a game, and then make up something that you can remeber with your team. You'll probably want to have signals for things like;
Contact
Indicating a flanking move
use a grenade
stop
move out
fall back
There's a hundred different things you could add to that list, but remeber to KEEP IT SIMPLE STUPID. Remember that some things are too complicated to be relayed by hand signals.