I'm going to teach you a simple throw. It is called O-Soto-Gari (Large Outer Reap).
There are three parts to every throw. 1.Off-balance 2.Entry and 3. Execution To get the off balance first put you right hand on your opponent's (left) sleeve. Grab their lapel with your left hand. Turn your hands like your turning a steering wheel to the left. While turning your hands step with your left foot about 5 inches to the left of their right foot (your left). Swing your right foot between your left foot and their right foot. Then reap your right leg back toward you colliding with their right calve. Watch this demonstration video to get a better understanding of the throw. http://www.youtube.com/watch?v=sf86Ua0twKw&feature=related