I do have the disks, they are pricey but you will pickup some good information from them. Is it worth it? that is hard to say but I did learn and feel more confident in what I am doing. I decided I better learn to tune mine was getting harder to get it right with mail order tunes. I was able to take my time and make adjustments in smaller steps till I got it right.
There is tons of info out there and you will pickup most of what you need on the internet
www.hptuners.com has a good site and good forum. Plus tons of examples of tunes to sort thru.
Good luck
Dave