Well, you of course need a map making program, so you'll need Battlecraft42 (BC). .
If you're mapping for anything other than classic BF (I see an AH-64 on your sig), you'll need to find the mod's ".lst" and ".cfg" files. They tell BC what objects to display. You can find references to these files here on this site, on the BC forums, and by Googling it.
If you want to change any units (the best part of making your own maps is you can include any units you want!), you'll need the Mod Developer's Toolkit (MDT). There's tutorials there too.
Also, Silversound wrote a little tutorial to set up a shortcut for testing maps, have a look .
I'd avoid clicking "Test map" while in the BC program, as it can sometimes crap out. Silversound's method works much better.
Hope this helps! 8)
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