Crashes line 36/38 with index out of bounds.  Changing the index to 0 in both cases.

As to your problem:
-Line 59, you set GL's color to black.  Set it to white.
-Scale Z by 255.0 on line 82.

Actually, if this is your first OpenGL program, I'm rather impressed--you've gotten pretty far.  Tips:
-Change line 38 to not fullscreen.  You'll find this is easier to debug.
-Functional programming for right now.  OO design just to wrap up some functions is overkill.
-Be sure to only load your textures once.  Take it out of your draw method.
-Don't use GL_LUMINANCE.  Use GL_RGB, and GL_RGBA.  If you're all for speed and are feeling up to it, always use GL_BGRA, because that's often how the GPU represents it internally.
-Clean up after yourself with glDeleteTextures.  Eventually, you should make a texture class for all your textures, and you'll put this in its destructor.
-Check out some tutorials.