SBS exchange setup

Hello,

I am having some trouble setting up my exchange server. Here is what I am up against. I just started this job and the network was already setup. Here is what I know so far. We have a DSL connection, that is connected to a LinkSYS router, which is connected to a Dell 24 port power connect switch(unmanaged), which most of the computers are pluged into. We also have a LinkSYS wireless G router which is pluged into the wired LinkSYS router. Our DSL has a dynamic IP. I am not sure how to set up SBS to use the dynamic IP address. ANy ideas? Should I amke the push to get a staic IP, or doesn’t matter?
Any help or tips are greatly appericated!!!

Darrell