User blog comment:NeonSpotlight/I am NeonSpotlight, ask me anything :3/@comment-24599204-20140227101229/@comment-3308937-20140228143236

People may snub the basic wikia help articles but they're actually not all that bad for beginners. The big one is simply Help:Editing.

Regarding finding things to edit, patch times are always going to be the biggest guaranteed source of edits. I made a guide for editing during patch time: User blog:NeonSpotlight/NeonSpotlight's Guide to Editing: Patch time.

As I posted in another comment here there are also my compendiums of editorial knowledge (Version 1, more in-depth and Version 2, simpler) which give more LoL wiki-specific editing tips.