The MAXNC10 is a simple three axis machine if I recall correctly. You can probably retrofit this with Mach3/Mach4 pretty cheaply. You will need a new Breakout Board and depending on the stepper motors and drivers that might be all the hardware you need. If you have a newer computer that does not use a Parallel port you are best to buy a USB BOB, like the Ethernet Smooth Stepper, but there are others.
You need to confirm exactly what is installed on the machine. The kind of power supply, stepper motor and sizes, what kind of stepper motor drivers. Post a picture.
Actually it is not a very complex process but for someone brand new there is some learning curve.
Software comes is several flavors, Cheap like LINUXCNC free but takes some knowledge to get setup and working. Mach3 big support group probably easier to setup than Mach4 it will cost $150 but lots of people use this software, pretty easy to setup as well. There are some newer software packages as well as other low cost controllers as well. Budget will kind of dictate which why you should go.
Russ