Home network with wrt54g

I am attempting to set up a home network consisting of two desktop computers , a wireless notebook, and an xbox. My notebook has a built in intel wireless adapter, the wireless desktop has a WMP54G wireless card. I already have a wrt54g router, and a friend is getting a new router and says I can have his old one.

I currently have my modem and router wired to one computer and wirelessly connecting to my laptop and the desktop with the wmp54g.

What I would like to do is set up my Modem and main router wired to my xbox. I would then like to have it wirelessly connect to the built in card in my laptop, the wmp54g card in one desktop, and hook another wrt54g router up to the other computer. I am completely capable of putting dd-wrt on the routers. I am curious if it is possible for all of this to work together in this setup, an if so can anybody give me some info on settings or links to somewhere that would have the information I am looking for.

Sorry if this has been gone over tons of times, I searched but could not find the info I was looking for.

Thanks