I got a call today about doing some headshots of some doctors tomorrow. They said they will be wearing black suits so bring a white or grey backdrop. Can anyone help me with the best setup on this. Should I use white or grey? How many lights should I take?

You could probably be effective with as few as two lights and a reflector if you have one (one key light, one background light, reflector as fill). If you've the space and equipment, a third light would be nice to have as a separation light from above and behind, although you would not want it to be, say, modified with an umbrella, which would spread the light too broadly. If you take the white background, you could go high key and lose the separation light-- overexpose the background by a stop or so over your subject exposure-- you'd need your subject about 5 ft in front of the background to be safe from shadow, etc. Hope this is helpful. . .