Roger if you have the USB board and software, I believe no import is necessary. It will load DXF files.

If you don't then just start with a blank drawing in SU, and Select file|Import. Select the file and adjust settings accordingly; I forget what they are as I am work with no SU, but I usually take the defaults.

If these are ready to cut parts you will need to create faces on the parts. I remove a simple straight line on each part, and then re-draw, and it creates a face 99% of the time. There are also plug-ins that will assist with this if that fails, but I find the above method the quickest, when it works.

After that just arrange to fit on a sheet of wood or foam that you defined within the phlatscript, and use the PhlatScript to apply cut lines, tabbing, etc.

If what your after is more complicated than that, just let us know exactly what your after and what you have to start.

Also check out the Sketchup form on here. TONS of great tips and videos.