Basicaly you choose the texturing layuot that best fits your model (under polygons->Texture) then you open the UV texture editor (panels UV texture editor) then take a UV snapshot, export it out paint it, then map it as a file texture to the model and thats it in a nutshell, its far more complex than that in reality (or I find it is).

Like PBman said do a google search for uv texturing tutorials.