Below are some of the pages I found most interesting:
CNC Retrofit Kits
GCODE 2000 and TTFtoDXF I found GCODE200 very helpful in displaying the gcode in graphical format, TTFtoDXF works great!
KellyWare KCAM Windows 95/98 CAM solution that reads DXF's - see above ;-)
Yeager CNC Pro Not too happy with the shareware limitations, but looks interesting....
WoodWeb CNC Forum - RECOMMENDED!
Majosoft - Great engraving site, lots of info
Quick Step KCAM/DeskCAM competition
DanCAD33 DanPlot supports a motorised C axis for a centered knife for vinyl and carving. dancad3d now supports helixes and spirials, and has a built in optimiser.
This list is not even slightly complete! Check back often, as I am continually adding to it.
That's all Folks!