Help with Home Network

[Vesuveus]

I'm having trouble setting up a home network. Here's my situation:

I have 3 computers. 1 XP (sp3) laptop, 1 XP (sp3) desktop and 1 Vista (sp2) laptop.

I have a wireless modem which connects to high speed internet. The XP laptop and the Vista laptop are connected wirelessly to the modem. The XP desktop is hard wired to a router (Vonage) and that router is hardwired to the wireless modem.

What I want is to be able to share the printer and files within a home network.

The printer is connected via USB cord to the XP laptop. So far I have been able to print documents from the Vista laptop and access files on the XP laptop from the Vista laptop.

I have not been able to access files from either xp laptop or desktop from each other.

I've run searches on how to set up the network, but when it comes to accessing the Shared Documents folder, I cannot gain access to the other computers.

Any help is greatly appreciated. Let me know if you need any more information or screenshots to help.