Looking for help in converying AutoCad 2002 to NC

I need help. I know how to draw in Autocad 2002, but is there any
special things I need to do like draw on diffrent layers or
something to prepare my DXF for conversion to a NC file? Do they
need to be saved in certain versions of DXF? The reason I ask is
Autocad allows you to save DXF's in 2002, R14,R13,R12 and It seems
most of the Demos for conversion don't even recognize anything but
R12 DXF files. So fare all attempts have been a mess (mEaning, the
CAM software produces odd results or the paths don't flow correctly.
Anyway, I thought I would ask you all for pointers, tips or best yet
how to's that you may know of. Possibly some DXF to NC programs or
easy to follow CAM software demos. I'm open to any ideas. I want to
figure this out and get to cutten.

Thanks

Shawn