Videos

You should implement videos on how to play certain champions. In the game. Because let's be honest here, from what I have seen, the only people who watch champion spotlights are the people who visit the boards. The rest of the League community pick up champions and expect to be good at them right off the bat, or they watch some professional person play that champ and decide they wanna do that too, because hey, apparently they're good enough.

You could also implement tutorial videos on how to play roles. They probably should be made by professional League players though.