That's why I've done this whole site. Knowledge is power. Read as much as you can. Get advice from those in your area who are successful. Write letters to people whose websites or newsgroup posts impress you.
Preparation is the key.
Therapy is where you should start. It will help you determine how important this is to you. It will also help you sort out your emotions. Most people have fantasies or misconceptions about transition. Therapy can help you prepare for the realities of transition, and how to handle both the pleasant and unpleasant parts.