About This File
There's no need to explain anything really, just look at the test map I made in Hammer and check out all the files included in the archive and where they go.
I assume you are familar with Source vmt/vtf files. If you can't figure it out on your own you suck and you shouldn't be mapping (yet).
challenge_test.vmf - this is the source of the map, open it in Hammer
VGUI template.psd - this is a template for making the Bonus Maps graphics for Photoshop (I use the VTF export plugin)
maps/challenge_test.bsp - the actual map
maps/challenge_test/challenge_test.bns - file to make the map appear in the Bonus Maps menu with the Challenge options
materials/VGUI/challenge_test.vmt - logo texture VMT file
materials/VGUI/challenge_test.vtf - logo texture VTF file
Apparently you can't make challenge maps without that fucking elevator entity which is a shame because I don't want it in my maps obviously. Hooray for Valve.