In the XP-Win2000 Networks things are not going to be any different, let the Nics obtain the IP Automatically, to check for the IPs in any XP/2000 computer go to the Command Prompt and type ipconfig.
You should have the Nic connected to the router with an IP in the range 192.168.xxx.xxx and the one connected to the hub in the 169.254.xxx.xxx range (Remember to add the 169.254 range in the ZA settings in the Win 2000 machine if ZA is there).
Once you know the IP of both machines ping the other machine from the command prompt (ping 169.254.123.231 for instance) if the ping is OK (You will get a reading) your next problem will be about user rights and passwords, from here the Network setup is different than the network with Win 98, but it is also a lot more secure.
You will need to create a user with the same user name and password in the other machine as the user you are login in (If somebody tell you to just activate the Guess account, DO NOT do it, that will mean that anybody getting access to your network can run around wild with no restrictions)
You will have to create the Share folders in Windows XP/2000 and grant that user access Rights in both the Share and the NTFS rights if you are using NTFS in that partition.