NASA florida region has a good program, good classroom sessions and on track instructors. one of the more structured track day driving organizations. i'm sure the program is basically the same in all the regions. definitely worth joining up if you want to spend some time on the track. gets you a subscription to grassroots motorsports as well.
i'm sure others will chime in, and there is lots of info on the internet about track days, but i will offer two tidbits that i think will help make it all a lot easier:
1) find a local club that runs autocross events and has practice days. this will get you prepared in a environment with much less pressure than a track day. plus at a practice event you can probably get to ride with an instructor or experienced driver, and have them ride with you. lots of the tech stuff is similar, and you will get an idea of the basics. i know it is not the same as a track, but it is a step closer and a bit safer for learning. probably a lot cheaper too, we charge $40 at our practice days.
2) great book - "secrets of solo racing" by henry watts. it will explain a lot, for both autocross and track days.