Mark,
For a good description of what the program does, just click on the words
Guitar Pro. You should notice that they are in a different color. They are a direct link to the Guitar pro site. There is a demo, and also a free download for a temporary program so you can sample it. I forget how much it costs, but for what it did, it seemed relatively reasonable.
I still buy the lessons, but have not yet purchased Guitar Pro. I just use the .gif file of the tab and listen to the MP3 file and watch the video. Once you get Guitar Pro I believe you can also write out and tab out your own stuff as well as play the stuff and read the stuff that Kirk creates.
Hope that helps.