Getting started

So here I am and trying to figure out what I need to know first before mapping like a madman :) It will be a custom map for my favourite game Contagion. Contagion is a good zombie game with realism :) It use the source engine and allow us players to create custom maps. There are many game modes out there and the best one imo is the escape mode, it is basically a objective based map and the goal is simple...you need to ESCAPE! The many random escape routes makes it replayable but it has it's limit :P

This is my first time that I shall seriously work on a map until it's done.
I only know the basic stuff from the hammer editor...but it was a long time ago. I was doing a small test map for my clan in a source mod game until I got bored and stopped mapping :x

For starters, I started to reread the book "Half Life 2 Mods for Dummies" that I bought long time ago. That helped me to remember a lot of things that have been forgotten :S