Hello

I'm interested in creating a custom zombie map.
I've never used modtools or such things so where can I inform myself about making a custom map and from where to start?
What do I need...?

Am planning to re-make a MW2 map, so I was wondering, is it possible to convert the whole map or I have to re-make it from scratch? How to use textures/models from MW2 and then add them to WaW?