I strongly second Max Eberle's Power Pool. It's the best instructional video I've seen to date, and he offers information on stance and stroking that can't do anything but help.
To my eyes, Max's fundamentals are as good as anyone in the game. And he offers clear guidelines to put anyone into the same solid positions. His approach is simple, yet explained fully with lots of useful insights into potential pitfalls and drills to monitor one's progress. For example, regarding grip, Max offers there are many ways to grip the cue, and he shows different methods, while describing the advantages and disadvantages. Then he tells what he does and why.