So League of Legends is a Defense of the Ancients spin off. I never played DotA, but I am greatly enjoying LoL. These games are classified as MOBA games, a sub-genre within RTS. The key difference that I've observed playing SC2 and LoL is that LoL is all micro. In an RTS like SC2, macro is necessary so that you have units to fight with, and sometimes a large enough army will just make micro irrelevant. However, in LoL, you control one hero unit, so everything is about microing that one hero unit. Incidentally, my SC2 macro needs work, but my micro is awesome. So if we play on a team, share control and I'll micro while you tech and macro.
My main is Sivir and I feel she is perhaps the best champion in terms of how much she teaches you about the game. Like most RPGs, there are archtypes of characters. You have your Tank, DPS, Mage, and Healer/Support. Sivir's primary role is that of a DPS. She fills the role exceptionally well in larger team fights as her abilities allow her to hit multiple targets simultaneous. To further fuel her team oriented playstyle, her ultimate ability is a group buff for all allies in the area, increasing attack speed and movement speed.
So, what about Sivir makes her so great for learning the game? There are many aspects important for the game. All of these aspects directly or indirectly affect the win condition: destroying your opponent's nexus.
Pushing (direct)
Leveling/Farming (indirect)
Team Fights (indirect)
Ganking (indirect)
Map Awareness (indirect)
Pushing is the act of destroying enemy minions and towers so you can "push" closer to the enemy nexus. Towers must be destroyed before the nexus can even be targeted, and towers in a lane must be destroyed in sequence. Thus Pushing is the only direct method to victory.
Sivir is the queen of pushing. While many come close, there is no champion that can both destroy minion waves and destroy towers as quickly and efficiently as Sivir.
Leveling/Farming is what I consider to be the second most important thing. Often times even if you have a bad matchup in a fight, you can still win if you out level your opponent.
Sivir, being an excellent pusher, likewise accrues XP and gold faster than most champions. Thus while she may be weaker than other individual champions in a stand up fight, her superior equipment and higher level will oftent allow her to win fights.
Team Fights are when you and your allies gather up and fight the opposing team. Sivir's role is often to sit back and allow her ricochet ability to bounce her attacks between enemies and thus damage all opponents quickly and efficiently. As noted before, she can also use her ultimate to boost herself and her team.
Ganking is when someone tries to ambush someone else. Frequently the ambush involves stealth characters of hiding in bushes waiting for opportune moments. In these situations, high burst damage is valued. Sivir's Boomerang Blade is one of the largest sources of burst damage in mid game. Incidentally, Sivir is also fairly weak if she gets attacked, so she also focuses on not getting ganked frequently.
Map Awareness is knowledge of the surrounding environment. This is probably more important than all of the above, because without map awareness one cannot push, level/farm, team fight, gank, nor avoid ganks safely.
Needless to say, in order to play Sivir properly, one must be aware of all of these aspects of the game. I've gotten pretty into this game and recently I've started working on my first guide that details how to level and thus come back from a poor early game.
http://www.leagueoflegends.com/board/showthread.php?t=477680
Current Games and Projects:
Computer: League of Legends
Computer: Team Fortress 2
Computer: StarCraft 2
Computer: Warstorm
LARP: Live Effects (Wyrd, Veil, Lanaque, Messina, & others)
LARP: TwinMask
LARP: Fighter Practice (El Segundo)
Book: Art of War by Sun Tzu
Book: Book of Five Rings by Miyamoto Musashi