It's a fun (and addicting, lol) game with a monstrous learning curve.
If you love being a tank that turns the tide of an entire game with a decisive move, try
Amumu. His ultimate is an AoE that stuns and damages. Also, his regular moves are all about damage to an entire team. His Q is a skillshot that pulls him to an opponent, stunning them. His W is a toggled AoE DoT, and his Q is a click burst of AoE damage that gets cooldown reduction for every time Amumu is hurt.
Also, his passive is that his auto attacks reduce enemy magic resistance
😛
Here are some good sites for champion build guides and other info.
http://solomid.net
http://mobafire.com
http://leaguecraft.com/
http://leagueoflegends.wikia.com/