G5 information is at

http://www.apple.com/powermac/performance/
http://a352.g.akamai.net/7/352/51/e9..._TO_062303.pdf
http://a192.g.akamai.net/7/192/51/eb..._WP_062303.pdf

Apple software development is at-

http://developer.apple.com/

ATI graphics information-

http://www.ati.com/
interactive radeon demos abound:
http://mirror.ati.com/vortal/r350/static/demos.html