Edit iptables in Debian 3.1

I am a newbie on linux. Can anybody help me edit an iptable on an existing server so I could add another subnet to be able to access the server via the Web. Please include a detailed step by step instruction as I am still uncomfortable using Debian linux. Do I need to login as root to be able to do this?

Thanks a lot

Marlon

marl - - 2006, February 14 - 1:17pm.