yeah, practice in you room, your neightbourhood etc, get a feel for diff lighting conditions, and get to know your camera well before you try to take pics of ppl (they get irritated when they hold a pose for 1min< while you find out how to adjust white balance etc)
also, a good place to start is the library. borrow books on digital photography, photographic lighting, or whatever catches your fancy. with a 40d, there are loads of things you have at the touch of a button good luck!
welcome
what lenses you having? can go chinatown/esplanade/merlion park to make some shots... i do my first time outdoor first because it's easier with brighter lights.