You might want to have a look at one of the "relatives" of NetHack. Have a look at the Roguelike Games Home Page for this.
The most voluminous site after mine, which also has quite a lot of spoilers that are not found here, is Sasha Wostmann's site.
Lots of ideas for this page are from Michael K. Neylon. Michael has made an alternative NetHack Home Page available.
Some other links were shamelessly copied from a NetHack page by Viljo Viitanen.