Usually depends on the processor you're using, as well as whether or not you're loading any sort of boot ROM on to the board.
I did some assembly on a Motorola Coldfire processor a few years back and my school had put a basic boot ROM on to the board...starting address was 0x10000. However last year my school performed massive upgrades to Coldfire2 processors and put a modified Janus boot ROM on the system so user addressable memory started at 0x101000.
You mentioned that this is for a class? Your best resource would be the prof, or the lab guy who administers the boards.