This site contains a bunch of softcode programs for use with MUSHes... be careful. A lot of these links seem to have died lately.
Javelin's Guide for PennMUSH Gods
This site explains how to set up and run the PennsMUSH server. This is an excellent instruction manual for any beginning admin, especially those who intend to run their own game.
The MUD REsource Collection
Again, as in most other cases, be careful of things designed specifically for MUDs... MUD interfaces are not exactly like MUSH, and occasionally you can run into some problems. However, there are lots of good resources on this page.
The MUD Connector
This site lists many MU*s and their addresses, as well as a little bit about them.
The MUSH Warehouse
This site has a number of different MUSH resources and lists many MU*s and their addresses, as well as a little bit about them.
Amberyl's MUSH Mannual
This site has a copy of Amberyl's MUSH Mannual for those who are interesing in learning how to code or build in Pennmush. Very informative.
Javelin's Guide for PennMUSH
This site provides anyone interested in starting their own MUSH a guide on how install and get PennMUSH working on their server.