Wireless Printer (help? I am trying to learn.)

Hi! I'm having some issues with a wireless printer, and I also have a couple friends who are dealing with the same sorts of issues.

Basic Info: Windows machines, and printers with built in wireless.

The setup for the printers works just fine, documents can print, and the computer sees the printer as online. After a while, the printers will start to appear as offline even though they are turned on. I am not sure if the wireless router is giving them different IP addresses and windows is not seeing the new ip addresses or what exactly is going on.

Does anyone know some good things I could do to troubleshoot the issues, or solutions I could try? maybe a decent site I could find more information on ways to troubleshoot wireless printer issues like this?

Any help would be greatly appreciated!