Use the left and right arrow keys to move, press the 'S' key to jump, and the down arrow to crouch. The up arrow is used to open doors. To go into a roll, either hold the down arrow on a steep slope, or hold it while mid air to land in a roll.
Hey, this guy's wearing pants!
Square Enix has launched their Dragon Quest 8 Official Community website called SlimeKnights. I'm a huge fan of the series, literally the second console game I ever played, after the original Super Mario Bros. game, was Dragon Warrior I (since you couldn't avoid playing Super Mario Bros. - it came in the Nintendo box).