Useful Sites

• Sourceforge.net - Provides a large collection of open source software for many platforms. Plus provides free hosting for open source developers.
• Freshmeat - freshmeat maintains the Web's largest index of Unix and cross-platform software. Thousands of applications, which are preferably released under an open source license, are meticulously catalogued in the freshmeat database, and links to new applications are added daily.
• rpmfind - Provides software packaged in RPMs for a variety of distros, with a fast RPM search engine that supports finding individual files within packages, and several mirrors. There are many other RPM search engines as well - RPMfind is probably just the most well-known, in the English-speaking world anyway.
• http://www.tldp.org - The Linux Documentation Project is a community effort to create a distribution-independant knowledgebase about Linux.
• LinuxPackages - A source for community-built Slackware packages with many other resources.
• Apt-Get.org - A great source for unofficial, backported, and other Debian packages.
• List of opensource packages or free tools for Linux - A great source for Opensource packages in different categories.
• LinuxISO.org - An excellent source for ISOs for your favorite distro.
• Linux Help - ISOs - Another good source of mirrored ISO images of popular Linux distributions.
• Nabble Forums - Nabble hosts thousands of technical forums on open source projects. It has a clean UI for browsing and also has a good search.
• Distrowatch - News about release announcements of Linux distributions and *BSDs.
• The Linux Kernel Archives - Lists all the latest kernels releases.