Links
ubuntu.com
linuxmint.com - If you’re looking for Ubuntu with a little lime twist, this may be the distro for you.
ubuntuforums.org - The prime source for guides, fixes, and general discussion regarding Ubuntu.
ubuntuguide.org - A fairly up-to-date source for lots of how-tos and guides.
psychocats.net/ubuntu/ - Has some harder to find info and guides.
distrowatch.com - Lots of linux news as well as a detailed source on many of the most popular distros in the world.
getdeb.net - Provides lots of software packages not in the repositories (or updated ones).
gaming.gwos.org - Ubuntu Gamers Arena - Database of lots of Linux/Ubuntu games and installation guides.
happypenguin.org - Not Ubuntu specific, but lists lots of new and old Linux games.