Setting up 2 wireless routers

Maybe someone can help me out here. I want to set up 2 wireless
routers. Here's why.
I have 2 Tivos and 1 Xbox 360. My 2 routers; Linksys WRT54G and D-Link
Dir-655.
I would like to use my Xbox 360 to access the Linksys wirelessly and
have the D-Link connected via ethernet to my desktop and the 2 Tivos.
The Tivo's are able to transfer shows to each other as well as my
desktop therefore the transfer speed would be much faster if I just
keep them wired. Nothing will be connected to the Linksys wired. I
also want to be able to access my desktop from my Xbox 360 so I want
my network to be seen as only 1 network. It would be nice to only use
1 router but when I bought the D-Link I didn't realize it wasn't
compatible with my Xbox 360's wireless adapter but the Linksys is so
the only thing that will be connected to the Linksys wirelessly is the
Xbox 360. I'm also running DD-WRT firmware on the Linksys.
I don't know what kind of configuration I need to set up on the
routers nor if I need to disable DHCP or what. If someone can tell me
the steps I need to take I would appreciate it.