Opengl Math Cheatsheet
http://www.opengl-tutorial.org/miscellaneous/math-cheatsheet/
Visualization of Math Physics
http://www.falstad.com/mathphysics.html
A very good tutorial about linear algebra, it visualises the concepts!
Matrix (GLSL)
http://www.opengl-tutorial.org/beginners-tutorials/tutorial-3-matrices/
Ming Wai Chan 