1) Make the computer you want to act as a server have a static IP address
2) You are going to have to do alot of port forwarding for your router...
2a) The easy way is to DMZ your server ip address but its not safe
2b) Port Fordward FTP, HTTP, ect... like gaming things like that you know.... just mess with the port forwarding page and you will get the hang of it.
3) If you would lke to use a DNS address instead of trying to remmber your dynamic ip address you get from the ISP, you can activate the dynamic dns located usually under your tools in your router... this way instead of remembering the numbers
you could type: umm kickbutt.homeip.net this homeip.net can by aquired from www.dynamicdns.com
i tink its called the kickbutt would be the subdirectory which would lick it to your router and forward the dns name to your router insteadof remembering the numbers. Got to remember ... most residences only have dynamtic IP from their ISP most businesses have the static.. little bit different here.