All information here: http://maurits.tv/data/garrysmod/wiki/gmwikisearch.php

yeah, but i dont understand it.

I have a nice idea for a Zmod server, here is:
PvP mode
Monday to Wednesday
rules:
-Slow Zombies
-Big Maps like gm_Atomic ir Big City(Whatever)
-Few itens
PvE mode:
Friday to Sunday
-Fast Zombies
-RDM or any kind of PvP is not allowed resulting in a ban
-small maps like gm_construct or apartmentcomplex(whatever)
-lots of food,drink,weapons,ammo,etc

OBS:
-Dont biching on PvP mode about being killed
-Dont kill players on PvE mode because is player vs environment
-enjoy

Ah! So you are wanting to host a server! You need to port forward then. To port forward, you need your IPv4 default gateway. Simply go to the network and sharing center, click on the blue bit on Connections: (Your network name here) and hit details to find the IPv4 default gateway. Simply put the numbers in the adress bar on google chrome or internet explorer and it should lead you to your routers control panel. Since I don't know who made your router (2wire, Access, ect.) I can't really guide you any further. If you are willing to put your routers manufacturer I can help you further. And no, this won't put your network at risk. All you need to do is look on your routers control panel for a company name. I hope I can help you further!

dang man, im sorry but i dont know that much about cpu's and computers man, just leave it ll play the official pve all the time xD