ITT: learning how to seperate a runescape-specific issue (running the server) from a general internet connectivity issue (forwarding ports).
Don't worry, you're in the right section. I suppose you're running your connection through a modem/router in which case the port forwarding will have to be done there. Also make sure you've allowed the server access through your firewall.
How to access your router:
1] Open up cmd.exe, type in 'ipconfig | find "Default Gateway"' without the single quotes (try removing the find part if it returns nothing and search through the output manually)
2] Visit the returned IP address, login using your modem/routers user/password combination (call your ISP for help if they supplied it)
3] Browse around until you find the option to forward your ports
