Multi-Router Home Network

So I have a Linksys wireless gateway/router/switch and connected to that is a standard linksys 4-port wire router/switch. I have a windows xp machine connected to each router. I have been unable to get the computers to talk. I realize that I need to use port forwarding. What I can’t figure out is what port/protocol I need to use. File and print sharing is enabled on both computers as well as multiple network shares. What I’m trying to accomplish is as follows:

-Access network shares on both computers
-Remote desktop functionality
-Remote management functionality