I'm attaching a quick printscreen. As you can see I use four lights to light the scene, all of them around .2 intensity. One is on the top (this is casting the shadow), and there are 3 more roughly 120 degrees apart around (one of which is at the back). And I use 3 planes 120 degrees apart for some nice reflections and also these are lighting the scene as well because I set the colour value up to 2.0 (1.0 is the max white color). So this adds a lot of extra light this is why my light are relatively dark.

Of course none of this is written in stone, I'm sure I'll change around the lights a bit later on for better shadows, etc. But it's a base (for me).

I made a 20 min tutorial about how I usually set up a studio render in Maya and there I explain some stuff a bit more detailed, you can check it out on Youtube:

Studio Lighting in Maya 2011 with Mental Ray - YouTube