I built a Rascle CNC this fall with a kit I purchased from
@TB RC . As
@Fidget said Nerdnic has a build video that is very helpful and gets you through the mechanical construction and wiring. However it stops short of assembling the electrical control components. If you decide to build one and need help with that let me know and I can get you come info on how to do it.
One thing I would mention is that the parts list links are a little out of date and it has the cheapest places to get the componets before shipping, but after considering shipping cost I ended up ordering alot of the more generic parts from amazon as I got them quicker, and shipping was alot less.