Grab MOHRadiant [url=ftp://ftp.ea.com/pub/ea/pr/MOHAATools.zip:2b98c]here[/url:2b98c]. Regarding tips. Have alot of patience and look around for some tutorials.
Nothing more simple. This is the standard map maker for MOH. To set it up, open it up and make sure your Project Settings is set so that your textures show up in the program (File-Project Settings). For tutorials, check out this [url=http://www.planetmedalofhonor.com/map:a0401]site[/url:a0401].