Networking Windows 2000 and XP computers

I am trying to set up a home network. Right now, I have both the Windows 2000 computer and the Windows XP computer connected and running to the internet. Now, I want to be able to share files and printers, etc on both computers. When I am on the Windows XP machine, I can "see" both computers in "My Network Places" but when I try to click on the Windows 2000 computer to access it, it says it's "inaccessible." When I am on the Windows 2000 computer, I cannot "see" or access the Windows XP computer at all.. It doesn't even recognize it as part of the workgroup. Both computers are in the same workgroup, which I just named "workgroup" and both are logged on using the same username "Administrator".  I have tried a bunch of sites, including Microsoft Knowledge Base, which threw 199 articles at me that I do not have time to sort through and try, and sites like HomeNetHelp, PracticallyNetworked and Wown, I find a little confusing to sort through too.