As a start let me say that there is simply no substitute for buying a set of lights and doing some testing. Supplemental lighting solutions are so varied and site dependent that they are hard to give general rules for. But I will try. To start with you will really need 3 heads and two 800ws power packs. These can be units where the head is separate from the pack like on my Normans or self contained units like Alien Bees.
Here is a simple example shot recently for a magazine article. The first image is a regular exposure for the highlights. Notice how deep the shadows are. Too bring them up in PS would create a tremendous amount of shadow noise. The second is with a single 400 WS strobe head with a 5" silver reflector bounced off a white wall to the right and above the camera position. The head was positioned about three feet from the wall so that the fill is very soft. A light gradient was applied to the upper left to bring the center of attention to the center of the image. The object is to open up the shadows without destroying the sense of natural light and the beauty of the sunlight splashing the furnishings. There is a bit more work to do to this image, but you get the idea.