- Encounter Level Generator -This tool is invaluable for calculating encounters with groups of monsters/npcs that have mixed challenge ratings. You can also calculate the equivalent party level for groups of PCs larger than four, or which have characters of different levels. The generator even recommends appropriate treasure values.
- Gozzy’s Cartographic Emporium -This is, by far, the best random dungeon generator I have found on the web. The generators on this site will do buildings, caves or wilderness areas. (The wilderness generator is not as useful as the dungeon and cave generators, because the super detailed images make it difficult to interpret the terrain.) If nothing else, the layouts can provide inspiration for site-based adventures.
- Gamespp -(from Arsheesh) This link includes an extensive list of free, downloadable ready-made adventures, many from the official WOTC site. Excellent as inspiration or as a last minute save if inspiration fails to arrive.
- Dungeonmastering.com -(from Arsheesh) Another extensive list of links to pre-made modules. (note: there are a lot of repeats between this link and the one above.)