Native,
I started with a piece of 3/8" x 1" brass bar stock that you can get from knife making suppliers. Cut it the length you want, and lay out a small rectangle the size of the knife tang in the location you want the tang to go thru.
Drill holes at each end of the layout the same size as the width of the tang...on the Helle blades, 2 holes is usually enough. If the tang is wider, drill as many holes as you need. Now's when the hard part comes. I use a combination of a dremel with a small grinding tool, and a couple of very small files to square out the holes and make it to where the tang will fit thru the brass. It's not real difficult, just real time consuming if you want a good fit.
Also, some blades are not square where the tang joins the blade...some have a radius. If they have a radius there, you will also have to dremel/file the brass so that the radius will fit inside the brass also. I mostly use the dremel for that. It's not real important that it is a perfect fit...only that the back of the blade fits tightly against the brass, and the hole in the brass doesn't show any more than it has to.
Once that part is done, the rest is pretty easy. Drill a hole in your handle material and any spacer material you are using, and epoxy the whole thing together. I also like to pin the handle thru the tang with 1/8" brass rod. If you do that, make sure you anneal the tang where you are going to try to drill it. If you don't, you won't be able to drill it. I ruined about 5 drill bits on my first one trying. I leave everything square until it's all glued up and I have the pins in, then start sanding and shaping the entire handle. The brass will work with most woodworking equipment...I've even roughed shaped it with my bandsaw and a woodcutting blade.
Sorry this took me so long to explain. I've been meaning to do a build-a-long, but just haven't had time lately. Maybe after Christmas I can find time to do one and take pictures as I go along.