You can also access the in-game Game Guide (G key by default) while playing LE, or visit the Community Game Guide for the same resource outside of the game, though it offers additional and expanded information not found in the in-game version. I recently finished updating it with all changes made in patch 0.8.4.
Dammitt also added the in-game Game Guide resource to his LastEpochTools website with some additional information relating to Ailments, Timelines, and Dungeons.