Shader question: Combining two textures

[Clueless Newbie]

How does one use shaders to combine two textures? The textures in question is an opaque wall texture (curve.jpg) with bumpmaps, gloss, etc, and a semitransparent environment texture (curverefl.tga). I can get these two textures to work the way they should separately, but I'm having problems combining them. Does anybody know of a map with shaders that do this? Or a website with sample shaders that show how to do this? (google was not my friend in this case)