The draw shot can often be a challenge for beginners. Here is a good drill and technique advice to help:
And here are video demonstrations of draw shot technique advice, physics effects, and game situation examples:
Here's a good progressive-practice drill to help you improve your draw shot technique:
And here's a video demonstration of how to achieve dramatic power draw:
Vol. I (Basic Shot Making and Position) of The Video Encyclopedia of Pool Shots (VEPS) also covers draw technique in detail.