Major Distros

DistroWatch
PCLos
Mandriva
Red Hat
Fedora
Ubuntu
Knoppix
Debian
SUSE
Gentoo
Slackware
Damn Small Linux
Mepis
VectorLinux
Lindows

Pre-installed Linux computers:

Seascape.us
Ibexpc.com
System76.com
Magiansystems.com
Linuxcomputersystems.com
Linuxcertified.com
Penguincomputing.com
Emperorlinux.com
Damnsmalllinux ( Mini ITX )
Axiomtech.co.uk ( UK )
Dnuk.com ( UK )
Xtops.de ( Germany )
MandrivaStore ( France )
Linux-service.be ( Belgium )
Dell+Ubuntu and Dell/Linux-info
lxer.com ( A large list of addresses )

Linux News:

Linux Pipeline
Linux.com
Newsforge
Slashdot
Linux Today
Tux.org
Just Linux
Freshmeat (software)
Think Geek
OS news
LWN.net
Kuro5hin
PCBurn
Back issues Penguin Shell
TuxMagazine
Linuxgazette.net ( Online Linux Magazine )

Best mirrors:

Ibiblio
NLuug
UTwente

Bittorrent Downloads:
The Linux Mirror Project
Linux ISO torrent

Icons:

Art Gnome.org
Gentoo Icons
DigitalGarage
Tux ‘n Tosh
KDE-Look.org