Hey guys! I'm only Plat III right now, which isn't the most impressive, but I enjoy helping out in PvS games and I play them often. That said, I actually wrote a guide/ama/thing on the general discussion forums on the league site when I first hit gold V back in s3.
Some background info: I was actually around 500 elo s2 and started s3 at bronze V. I ended at Plat 3 after playing the whole season and I was quite proud of myself.
http://forums.na.leagueoflegends.com/board/showthread.php?t=3624446&highlight=delightfulunicow+gold+500+eloA lot of the info is outdated because of meta shifts and gameplay changes, but the majority of it is still relevant. Remember this is from the perspective of a (then) gold V so it won't really help out those of you in that tier/ranking now, but for those of you who are trying to break through past bronze/silver, I'm sure this will help!
Btw this was written when my name was Delightfulunicow, so don't get confused.
If anyone wants to talk to me personally for some jungle/mid advice (because those are what I main), my ign is Cloud Halcyon on the NA server. Feel free to add me and chat me up. But warning: I might remove you after a while because my friends list is full. In that case, just add me again.