I want to run a few programs on my wireless lan that require port forwarding... and ive come to an impasse... I need to disable my DHCP server.

How do I manually configure everything once i turn off DHCP? The computers on wireless are running WinXP SP2 Home, WinXPPro, and Mac OSX Panther.
A win2000 machine is also wired in.

I'm curious as to why you'd have to disable your dhcp server.

As for manually setting the information, probably easiest to just copy the existing settings that have been assigned

In windows, hit your command/dos window and do:
ipconfig /all

take note of the ip address / netmask / default gateway + dns servers

Each machine will have a unique ip address, rest will be the same.

Just allocate an ip address outside your dhcp range .. Also, you will have to keep an eye on the dns servers in case your isp ever changes them.