One thing the cheat sheet doesn't mention is how aperture, shutter and ISO interact. One of the blessings (and curses) of DSLRs is that they allow a wider array of settings than older film cameras (most film cameras don't support shutter speeds of 1/50 or 1/100, for instance, they go 1/30 -> 1/60 -> 1/125).
Anyway... the cheat sheet neglects to mention that when your light is correctly metered, you can manipulate the photo by making sure that the sum of adjustments among aperture, shutter speed and ISO is zero. That is to say, if you're taking a photo at 1/125 with the aperture at f8 and ISO at 400 and you want a shallower depth of field, you can open up the aperture 2 stops (to f4). When you do this, you'll need to adjust your ISO and/or shutter speed by 2 stops. So, you could move your ISO to 100, increase your shutter speed to 1/500 or move your ISO to 200 while increasing your shutter speed to 1/250.
The key is making sure that for every adjustment in one area, you adjust in the opposite direction in another area.