My only experience with LoL is playing vs. bots and the only thing holding me back is hearing how bad the community is for new players.
You know, I hear people complain about this a lot and I honestly don't see it that much in game. I occasionally play on a low level acct with my friend and his gf, both of whom have just started playing recently, and I don't think I've seen someone rage once.
In ranked I might report someone for being abusive maybe once every 20+ games. Based on my experience, if someone sees people consistently being abusive in chat then either they are instigating something or they have exceptionally thin skin and get offended at any type of criticism.
That's just my experience though, so ymmv.