Well it really depends on what materials you are using. If you are going with wood then I would search around for some 1/4in tracks that you can screw into the wood: http://www.mcmaster.com/#door-tracks/=xrlmtw
If you are going to do glass I recommend going the tempered glass route. That was pushed on the monitor forum quite a bit.
Just one word of advice to think about. I have sliders on all my smaller cages, they work great for the all of my other lizards, but when I had the Tegu in the smaller cage she was constantly shoveling dirt into the tracks making it impossible to slide open and closed, mind you this cage had a 6 inch barrier before you could even get up to the tracks, they weren't ground level, which is why on her big cage I went the hinged route. I would much rather have sliders but she already proved it would be a pain to constantly vacuum out.