This tutorial describes both how to create a custom face for you as player, and how to create a face addon to introduce more faces into your missions.
The OFPEC Command Reference contains details of all scripting commands available to the editor.
All you need to know about how to start editing.
This tutorial explains the mysteries of multiplayer editing.
OFPEC hosts several quality tutorials written specifically for the site by staff and members...
Register a tag, browse for addon keys...