I need to know how to set up a home network that will allow me to share files between all of the computers, share my two printers, and hopefully accomplish a few other media sharing things as well. Currently all of the PCs use wireless internet to connect to the internet, but not all of them discover eachother. I think that I just need to reset the network settings and configure a few things. I have a router, and wireless cards in all of my computers, the computers are as follows.
- one pc running windows 7 (this is the computer I would like to set it up on, I want it to be the main computer)
-two pcs running windows XP
-and one PC running windows vista home premium
Any ideas? Links to tutorials would be awesome!

Printer Media, Computers & Internet