Hello, EnduranceRobots.com made a video lesson how to make gcode for engraving
http://www.youtube.com/watch?v=xw8h0c5Vdw8

Some samples you can download from our web site: http://endurancerobots.com/products/...r-engraving-2/

If you have some questions, i'll try to unswer you!
Skype:george.fomitchev
E-mail: gf@endurancerobots.com