Thief 1 & 2 editing: Dromed
Dromed: Getting Started
Dromed Toolkit
Dromed FAQ
Wiki: The Dromesday Book
Forum: The Editor's Guild

Thief DS Editing
Download the Thief III Editor
Forum: Thief III Editor's Guild
Wiki: Fleshworks

General
Best Mission Release Practices
Guide to Custom Resources for dromEd