Allowing Outside Connections to LAN?

[Moncleared]

Hey guys,

I attempted to search, as I found most of my previous answers through that system. But, my question is, and if its been answered just hit me with a link and I"ll be happy:

I've setup my server for LAN right now, all my computers in my room can connect to my server so the LAN is working properly. My question is, my friend lives down the street and instead of him coming over 24/7 is there anyway possible for him to connect to my LAN from outside? Or if I'm using the wrong terms at all, is there any guide to set it up so that I can make my server, not really public, but avaible for that kind of connection?

Just to give you some background information, I currently am Behind a Gateway and a Router. (Gateway = Cable Modem/Wireless/Router all in 1). So basically my server is behind 2 routers before someone could get to it. I've been trying to logically think how someone would connect to my server by going through 2 routers, anyone got any advice? I would appreciate it a lot. Thanks

Moncleared

<-- PS, my current progression = EQ down, Kunark down, Velious up to Sleepers.