On August 25th, I started tinkering with the software for the CNC machine.  (Actually started earlier on Saturday, Aug 23, without much success).  Went back to Stepperworld.com, from where I bought the stepper motors, and checked out their recommended settings.  It turns out that the control board they supplied works with KCAM, a freeware piece of software they provided with the motors.  On their website, they also have a list of the appropriate pin-settings (at the bottom of the page linked here) to control the stepper motors through the parallel port, via KCAM.

Note - when you install KCAM, it will provide to programs: KCAM3 and KCAM4.  The pin-settings and tutorial on Stepperworld appears to apply to KCAM3.

I put the pin-settings in, and tested it out.  Seems to work!  I can jog the motors, set the motor speeds, set the "home location", and have them return to their initial position after jogging them around.  I can also load a G-code file and have the motors obey it (I think - there seems to be a scaling issue between the path and the actual motion of the motors, which means they may prematurely reach their end of travel - I have to find out where that gets changed in the software).  I could also load a G-code file created with LazyCAM.  And since LazyCAM can read .DXF files, and I know we can create .DXF files from Solidworks or AutoCAD, then I -think- that means that most of the puzzle pieces are in place!  We just need to jiggle them down so all the parts fit snugly.

:-)