I have Kirby Lambert's handle wrapping DVD, and it's pretty decent. I don't do things the way he does them, and absolutely cannot recommend the titebond glue he uses for the handles. I just don't see how he gets it to work. It's a foamy nightmare.
I get flat nylon cord from knifekits.com. Some guys are getting big spools of hiking boot lace from shoelace places. You can also search for cotton Ito cord in tons of colors. Sword restoration places have it. You want a foot of cord per inch of handle.
As far as the epoxy for the handles, nothing beats West System's 105 Resin and 207 hardener. Works well on paracord and any other fabric, hemp, and leather cord too. The epoxy makes some colors alot darker, so be aware and maybe test some out before committing to a handle.
Mix 3 parts epoxy to 1 part hardener and just brush it on with a small disposable paint or acid/flux brush. Prop it up and let it dry a full two days. If you try to do your kydex work when the handle is even the slightest bit tacky/soft, it'll be a disaster.
Check out some youtube videos on tsukamaki. Here's a helpful diagram too. (nevermind the paper triangles etc. I'm no traditionalist.) Just takes some patience and practice.