List of Halo Levels
From Halopedia, the Halo wiki
Here is a list of all the levels in Halo: Combat Evolved, Halo 2 and Halo 3. Contained in each level's page, there is a walkthrough, usually for Legendary difficulty, which should also work on Heroic, Normal, or Easy. Each page also contains transcripts for the level, if applicable. For a guide on writing a walkthrough, please see Help: Level Walkthroughs