Take a class at a local trade school or community college. If you're like a lot of visually inclined people you will learn best by doing. Then as our Scottish friend said, practice your arse off. And then, prepare for a lot more bad work than good, and don't lose hope. It takes a long time to realize the images you want to make, and it has much more to do with your mind than your photo skills. That said, the skills need to be cemented first so you can free your mind to make it do what you want it to. Good luck!
Matt
www.pittsburghfilmphotographer.com