Making maps for custom battles using the map editor

[Bombasticus Maximus]

Is there a well explained way to do this somewhere if so where as I want to make some. I have made one thats just adding:

custom_location		Scottish Highlands 2
{
	location		47	155		
	image			data/menu/custom1.tga
	sett_locked		yes
	summer			no
}

But thats not making one that by yourself.