Tales of Despair
Many people seem to wonder how to run some of the larger more involved areas in the game. The answer is to actually play the game as an RPG, and truly role-play your way through the obstacles and mobs. These narratives will give you insight on some areas and how to THINK in order to proceed through them without giving any specific advice or spoilers so you can solve the puzzles and mobs on your own, which is great fun.
If you actually read the game, and talk to npc's, use skills, etc, like you're playing D&D, you will succeed. Here are some extremely poorly written tales outlining some of the largest and most interesting areas in the game, both to assist you, and to share their contents with some people who may never get to play through that content: