Linux on Laptops -- great resource for getting laptops up and running. Often the links are distribution specific, but you can get the information you need.
Forums:
Mandrake Club -- yes, they want you to pay to join, but you can read the stuff in the forums for free, and the front page is basically a Mandrake blog.
Gentoo Forums -- check the Gentoo forums for questions that have been answered, or questions that can't be answered by our resident users
FedoraForum -- similar resource for Fedora, with a blog on the front page.
LinuxQuestions Slackware Forum -- another forum, this time for Slackware.
LinuxQuestions has many forums, check them all out.
Mailing Lists:
Slackware Lists
Gentoo Lists
Fedora Lists
Mandrake Lists
Debian Lists
Linux Kernel Mailing List -- make sure you read the FAQ
IRC:
Most Linux IRC channels are going to be found on
freenode (irc.freenode.net).
mIRC -- IRC client for Windows
X-Chat -- Graphical client for Linux (has a windows version that works free for 30 days, or you can find a binary somewhere else)
BitchX -- Text client for Linux
ircle -- IRC client for MacOS (if you have fink, you can generally get the Linux clients too)
Fedora IRC Channels
Debian IRC Channels
Gentoo IRC Channels
Other distributions and projects have IRC channels on FreeNode that may not be listed on their site, like Slackware (#slackware) and Knoppix (#knoppix) for example. You can do a
/list command when you are connected to find out all of the channels.
Software sites:
FreshMeat
SourceForge
Themes and backgrounds:
Themes @ Freshmeat -- huge library, used to be themes.org
MacDesktops -- I know it says Mac in the name, but some of the backgrounds are awesome, and they have high and widescreen resolutions
As always,
Google is your friend.
Other links:
Howtos that are Mandrake 9.x/10.x oriented, but apply to other distributions in many cases.