Training materials would be particularly useful, both for application software and general system administration. intended for non-profit volunteers and workers who want or need to be responsible for their organisation's computer systems. Such materials could also be useful for professionals working or volunteering for the organisations we're trying to help, who need to teach people how to use the new systems they're implementing.
For these materials, the slides developed by DD, and available at http://www.debian.org/events/talks could be expanded, maybe this should be a sub-project of the DDP (http://www.debian.org/doc/ddp)
A top level guide, one for administrators and one for users of the OS e.g to do this common task (such as getting an internet connection) you need to do such and such in the OS. This needs to be very basic.
Guides developed already for Ubuntu could also be useful, see http://ubuntulinux.org/wiki/DocteamProjects