To add some info to the discussion about hotshoe strobes vs. monolight strobes, the reason that monolights are so named is that there is a third alternative, that being a pack-and-head set up that uses power packs that control several flash heads. You control the flash output from the pack, rather than the head. You're will most likely see a pack-and-head system in use in a studio, though they can be used on location without any real problems. They offer a fair number of advantages, particularly in that the heads themselves are quite lightweight, making them ideal for putting on booms or in other situations where you might risk a stand tipping over. The disadvantage is that you are a little more limited with where you can put them-- if you had 5 monolights you could put them anywhere you have plugs, if you had 5 heads and a pack, everything would need to plug into the pack.