OpenGL Programming Guide - The Red Book
OpenGL FAQ for developers
EFnet OpenGL FAQ
GL Journal
Advanced Graphics Programming Using OpenGL
Code Samples from the Red Book
SGI OpenGL Samples
NeHe Productions
ZEUS CMD
Cg - nVIDIA
OpenGL Shading Language - 3D Labs
Shader Tech
Paul Heckbert
Pat Hanrahan
Rich Szeliski
Ralph Martin
Doug James
C.K. Shene (Curves and Surfaces)