Boz: technically speaking, the 180 degree rule confuses things when dealing with a scene that has 3 or more characters.. because the line can and will be crossed whenever a character turns to look at another in the scene..
It's not terribly complex, but it does take some 'spatial thought'
For a good helping of all the "camera angle theory" and whatnot you need check out "Film Directing: Shot by Shot" and "Film Directing: Cinematic motion" both by Steven Katz.
generally documentaries are more of a standard "interview style" or like the 5 o'clock news type of reporting coverage, so it's completely different worlds (usually).
airbayforce: you might consider talking to a local TV news camera person and/or some cable access people. Also check with your local cable access station chances are they offer a basic course or two that might help you quite a bit. In the mean time.. burn up as much dv footage as you can afford and find the time to shoot, because nothing will help you to learn better than just getting out there and doing it. You will likely develop your own 'style' too, but before you get to that, concentrate on the basics... framing, coverage, etc. Remember, Documentaries aren't usually known for their amazing cinematic camera moves, but rather the material being covered; be it a bunch of penguins marching across the frozen tundra to find their life mate, or some kids talking about how great it is to spend their free time in the park (both of these are actually real docs... the first of course being "March of the Penguins" which is in theaters all over right now, and the second being the uber long doc about a park in California somewhere that was listed as only being 20 or so minutes long that I fell asleep during at the student film festival I went to last year.. it was really more like 2 hours long, I slept on and off for about an hour after struggling through the first half hour or so and it was still going when I finally got up to leave. Ugh.)