The GNOME Documentation Project Web page lists current GDP projects and members.

The GDP Documentation Status Table tracks the status of all the various documentation components of GNOME.

Norman Walsh's DocBook: The Definitive Guide in an excellent book on DocBook, available both online and in print.

Docbook: The Definitive Guide is available in both printed form and on the web at: Docbook: The Definitive Guide

The gnome-docs-list mailing list is the main discussion area for all contributors to the GNOME Documentation Project. You can find out how to subscribe to this list on GNOME Mailing Lists. This is a rather low-volume list, so you will not be flooded with messages.

Internet Relay Chat (IRC) is a fast and easy way to get in touch with other GDP members. There are generally at least a few members here who can answer questions or discuss documentation issues. The IRC channel is #docs at irc.gnome.org.