You might want to take a look at some of the source code that Humus and NitroGL have made available for their demos, too. The OpenGL Extension Registry is also a good place to bookmark as it has the specs for just about every OpenGL extension.
Another thing to do is study up on the effects you want to accomplish. It's best to know exactly what's happening in an effect before you try and implement it. The math involved, the concepts exploited. . . it's quite important.