Ubuntu is a complete Linux-based operating system, freely available with both community and professional support.
Ubuntu is suitable for both desktop and server use. The current Ubuntu release supports PC (Intel x86), 64-bit PC (AMD64), UltraSPARC T1 (Sun Fire T1000 and T2000) and PowerPC (Apple iBook and Powerbook, G4 and G5) architectures. Ubuntu includes more than 16,000 pieces of software, but the core desktop installation fits on a single CD. Ubuntu covers every standard desktop application from word processing and spreadsheet applications to web server software and programming tools.
Site: http://www.ubuntu.com
Support: http://www.ubuntu.com/support
Cummunity: http://www.ubuntu.com/community
Also, the next version of the popular Ubuntu Linux distribution was released today. The Edgy Eft will include bleeding-edge Linux technologies, with many of the packages expected in Edgy to be beta themselves.
http://www.ubuntu.com/news/EdgyBeta
The final release of Edgy Eft is expected on October 26.
Ubuntu’s wikis and forum are extremely well maintained, it’s one of the friendliest distros for beginners I often visit their forum and recently came across with their nice blog; http://joey.ubuntu-rocks.org/blog/