Not to sound negative, but this seemingly simple request isn't really that simple to answer. There is no single definitive method and there are lots of ways to approach this, and even worse: the easiest-looking OpenGL code is actually the slowest
way to implement it (just to be clear, I mean glBegin/glEnd stuff)!
I will point you to Nehe's lessons starting at http://nehe.gamedev.net/lesson.asp?index=01
that have REALbasic code that should get you started (they run up to lesson 6, which covers texture mapping). That's how I started writing my GL classes at http://www.jcquan.com/REALbasic
and I learned lots (heck, I'm still learning!).
You might find Blake's OpenGL classes a good way to learn (they're six of them in this Games forum as of this writing), as they break things down into more easily-digestible chunks.