If you have no intention of going pro, then the absolute basic kit is:
2 standard 250W photoflood bulbs (main and fill)
2 flood reflectors (to focus the light, also great for backlighting)
1 spot reflector (to give more definition than the flood)
3 clamp-on units (holds lights to stands)
3 light stands (holds lihts up)
extension cords (to get power)
1 16x20-inch sheet of white cardboard (reflector for soft fills)
Plenty of thumbtacks or pushpins (holds up bacgrounds and other things)
Masking tape (same)
Enough electricity (ensure you don't overload circuits)
Some people recommend you start with a single light to learn the effects of the different placements can make.
Note that the setup above will be hot. The "models" will not like you after a few minutes under this setup. Going with more expensive strobe setups (such as Alien Bees, etc.) make it more comfortable for your helpers.
One big advantage: you can see what the lighting looks like as you set it up. Strobes will require you to shoot, look, reset lights.
Another advantage, you will spend very little for this setup.