I know pretty much nothing about CNC milling (I'm an IT/Electronics Tech), but our prototyping lab now has one of these Roland machines. It will be my job to support it, so I need to learn as much as possible.

My biggest question at the moment involves materials. From what I understand, this machine doesn't do metal, so what are some good prototyping materials I can get with a limited budget? I've used machineable wax, but that's it so far.

Also, is there an easy and reliable way to mark the measurement of the endmills? The PCB milling machine we have uses rings around the mills, but they are all of a fixed length. I've been measuring with calipers and hoping that it's accurate, but I feel that there might be an easier way that I'm just missing.