I would suggest just to use final gather to start with, just to get some nice lighting from the image starting low then moving up till you get a nice look, you can make a really great render without going for global illumination, caustics, mental ray materials etc etc, hell jsut use the HDR as a reflection map and switch off FG!Make this a bit af a rendering lesson, so you understand what each thing in the render settings does.

Also it will get your understanding of shaders up too, with the fresnell ramps etc.