Hey G - The 'nut' (if you haven't found out by now) is the slotted thingy at the top of the neck near the headstock that the strings sit on and in...and the 'bridge' is the opposite end of the equation...near the back of the guitar...and you'll want the strings to have a sharp angle over the nut and the bridge. I'd say if you're not too familiar with this stuff, it couldn't hurt to read as much "How a guitar works..." stuff you can find before trying to build a CBG. Though simple as heck to build, there are a few crucial little things that'll make a CBG work great or be useless --- Sharp string 'break angles' over the nut and bridge saddles being a major one. and you can mark where teh fret markers go by lining up a real guitar neck ontop of you new ne CBG neck and making marks where the nut and frets are located. and keep in mind where the guitar's bridge falls on the CBG body so you can put the bridge (a big bolt? a piece of wood? whatever works. And remember you can always make a string retainer above the nut and/or below the bridge to increase the string break angles -- you'll get much stronger tone with sharp break angles. Oh, heck, I just noticed others have already answered your question. well, more the merrier. best of luck --- ET

@ George Galen Sanders: think of the nut as the "bridge" at the top of the neck. It's what the strings pass over at the top of the scale/at the top of the first fret. You can use anything from a piece of an old comb to a machine screw or even a bamboo skewer for your nut. Your mileage will vary with any of these based on a bunch of different factors. Happy building.