Gary,
first set in your mind that this will take time to learn. Take it one step at a time.
I've only used Mach3 but what I'd suggest is look at the training material, videos, etc available for both. For me that has always been the battle. Software is no good without knowing how to use it. Last time I looked there seemed to be more training materials for Mach3 than Mach4 but Mach3 is getting old and requires either a PC with a parallel port and XP (some have had success with Windows 7), or an external motion controller board (UC300-LPT or Smoothstepper).
Take a look at other options too like UCcnc + UC300-LPT, by Cncdrive.com
As for what TP said, I couldn't agree more. I haunt another forum and get very irritated by how many "button pushers" there are. They seem to have a strong refusal to learn and understand gcode. As a matter of fact I just got tired of suggesting single stepping through gcode as a troubleshooting method, because it fell on deaf ears most of the time. Point is understanding the gcode is a very powerful tool. I'm not genius at it but I learnt what I needed to make life a lot easier for me.
Keith.