Official Links
Wizards of the Coast-- Owners of the D&D brand
Official D&D WebSite

Mac-related Links
Mac Dungeon-- you're here right now!
G.U.T.S.-- G.U.T.S. (The Game Utility Tool Set) is a flexible dice rolling utility
MacRPG Utilities-- Michael Schumann has a great list of AD&D and other RPG utilities
Mad Irishman Productions-- Mac fonts and character sheets by Patrick Murphy
Veggie Boy's RPG Page-- Sean Reynolds of WotC has posted some of his homegrown Mac utilities
The World of Argentairia-- Tseran has created a very cool character, list and table generator

Other Links
Role Playing Tips-- the website for Johnn Four's excellent (and free) RPG newsletter