Distributions

Ubuntu - (Xubuntu) The distribution I currently use
Debian
NSA Security Enhanced Linux
Linux Distribution List
Other Distributions
DistroWatch
LinuxISO

Laptops and wireless

Linux on Laptops
Linux and Wireless LANs
Wireless Tools for Linux
Software Suspend

Documents

Linux Documentation Project
Linux HowTO
Debian Online Books
Linux Newbie Admin Guide
KernelNotes

Miscellaneous

Linux WebRing
Linux User's Groups Webring
Users Forum
Linux Links
Linux Metapage
Linux Counter
Installing Linux from scratch (not for the weak of heart)
see also - linuxfromscratch.org
Terminal Server Project
Linux SQL Databases and Tools

System Testing

Linux Test Project
Linux Test Tool Matrix
stress
bonnie
bonnie++

Clustering/HA/Load Balancing

Linux-HA Project
openMosix
freshmeat clustering/distributed networks
kimberlite
piranha

for SPARC

SLXT SPARC-Linux Xterminal Package
Ultra Linux (SPARC processors)

Software (see also)

Linux Kernel Archives
GNU  what's Linux without GNU?!?
parted like Partition Magic - supports ext2, ext3, FAT(16/32), linux swap
Linux Lab Project
Linux GPIB Package
Comedi   drivers, tools, and libraries for data acquisition
GPIB-tcl
ksh
SourceForge
Macromedia Flash
AOL instant messenger
Yahoo Messenger
Real Player
sysstat   performance monitoring tools - include sar, mpstat, iostat and sa
GTKTerm   terminal to communicate with a serial link

For Kids

Debian Jr for Kids