Lighting is key, and multiple strobes are the way to go, with 3 probably being ideal (aimed at front, side, backdrop). At the very least use a strobe on the camera for fill light. Check out Adobe Lightroom for a good image processing tool, and its raw support is outstanding. Also check out
http://strobist.blogspot.com/ for lighting tips.
edit: Also, I've had good luck with big diffusers on my strobes - I'm using Gary Fong diffusers. They even out the light and give a more natural, less harsh look when lighting a subject directly with a flash.