You can make a string with one spool of material and a spool of serving, but a good serving tool helps a bunch. A string board helps (Flemish), but not required, and you can make that yourself. I'd mark it by string length, not bow length, as that is a shot in the dark.
I've been involved with two different string making videos. I think the second (How to Build a Great Bowstring) is a little better--the camera work is better, and there's more detail on endless strings, but they both have good information.
I've made well over 10,000 strings, and the video is the next best thing to sitting down with me and making a string. It's start to finish, no shortcuts and nothing is left out. I don't hide anything, and don't have any secrets. No smoke and mirrors, no "proprietary measures".
Depending on what part of TN you are in, you may be within a reasonable driving distance of me. If you are close enough, you can come to my shop and I'll help. If not, catch me at a tournament and I'll be glad to help. If you see me at a tournament, chances are I'll be set up with BCY materials and some great deals as well. First one will probably be the Pre-Spring Arrow Fling in AL, but I also plan to be at the TN Classic in May.
Chad