The Ubuntu Forums are helpful, if slightly chaotic. The wikis are better organized, but inconsistent and occasionally outdated. Now a team of users and contributors to the free Linux distribution have organized to create a beginner's manual for Ubuntu, to be included by default with the next release (Lucid Lynx) in April. The manual aims to include "comprehensive guides, how-tos and information on anything you need to know after first installing Ubuntu," and is, as you might imagine, being written in wiki form, so anyone can contribute. What newcomer topics and how-tos would you like to see covered in an Ubuntu manual?
http://lifehacker.com/5441494/ubuntu-1004-to-include-beginners-manual
A complete beginners manual for Ubuntu, featuring comprehensive guides, How Tos and information on anything you need to know after first installing Ubuntu.
Designed to be as user-friendly and easy to follow as possible, it should provide the first point of reference to any Ubuntu newcomer with lots of information in one easy to access PDF file. Plus, every six months there will be a new revision released to coincide with each new release of Ubuntu.
https://wiki.ubuntu.com/ubuntu-manual