Round Up: The "Starving Student" Off-Camera Light Kit
This is the basic Strobist kit I toted around as a photojournalist for 20 years. Doesn't look like much, does it? But you sure can do a lot with it.
The gear seen above is mostly out of date now, as this post was originally written in 2006. But I have updated it in Lighting 101, with specific, current recommendations. You can see that, here.