Is there an in-depth guide to affixes somewhere?

[FDru]

Or could anyone give a quick run down of how they work?

I know how to look up what affixes exist but really no idea how the game decides which affix can go on what item.

[imfratman]

sorry there is no quick anything in this game . there is plenty of videos available for you to view though. i suggest you start there .

[crush eat kill repeat]

Check out the website Grim tools. It has an item database that allows you to check out the prefixes and affixes of items.

An easy thing I can tell you is there are prefixes with the same name as the dual class combinations. Those prefixes give bonuses to one skill in either tree, with 3 possible combinations.