MYbook network on XP?

I have two XP PC’s on a network with linksys router. How do I get the remote PC to be seen by Mybook?

If you could reply with more details of what you have.

Such as I have WD Mybook , Essential, Studio and the model WDXXXXXXXXXXXX.

I connect it via USB, Firewire 1394a(400), Firware 1394b(800) or Ethernet to a computer a or b or to the wireless router?