Howdy!
adam_m,
Welcome to the Zone. :wave:
The answers to ALL your posted questions are answered here on the "Zone" in the various threads. The threads ben_jackson provided links to, are good places to start.
My advice to you is to determine what you want your machine to be capable of: ie. material to be cut(foam, HDPE, MDF, exotic woods, aluminium, even steel), size/thickness of material to be cut (this will determine your working envelope), tolerances needed for various materials, cutting feeds, rapid speeds, to name a few performance criteria. Along with performance criteria, you need to consider your budget, design skills, available tools, your building skills, electronics skills and your time constraints. The budget is usually one of the most critical aspect of any build. Who couldn't build the perfect machine(s) with time and an unlimited budget.
Once you determine your desired performance criteria, you then set out to design a machine to meet or exceed those criteria.
While doing your research, keep your performance criteria, build & design skills and budget, in mind. You have come to the right place to research/learn all there is to know about DIY CNC routers. The people here on the zone are ready, willing and able to share their knowledge and expertise.
Again, Welcome to the "Zone". Have fun reading/researching.
Randy,
I may not be good....
But I am S L O W!!