This type of article may have been posted previously, in which case I apolgize.
As a result of setting up the Milsim for FVA, I wanted a map of the field that was reasonable accurate and had a military style grid. I found some software that works well with most GPS units. I hope you find this useful.
You can read the PDF I created here :
I will try to add some detail once I have the Milsim finished.