Don't know Win2000, but for Win9x:
To Network puters you need to have a common Protocal and "File and Print Sharing" enable.
Both puters have to have "File and Print Sharing" enable by right click: Networking Neighborhood icon > Properties > Client for Microsoft Networks > Add
Make sure "File and Print Sharing" is in the "Primary Network Logon" window...And make sure Files & Printer access is enable in the "File and Print Sharing" window (locate under "File and Print Sharing" button).
I have use TCP/IP, NETBEUI and IPX/SPX for LANs, but I suggest NETBEUI (none routable)for speed and eases on setup.
TCP/IP is use when you want all puters to connect to the Internet (routable), then you have to set up IP Address and Subnet Mask.
To find out your IP adress click: Start > Run > then type WINIPCFG in the "Run" window (make sure you use Dynamic Host Configuration Protocol [DHCP], so you could get the correct IP address that your Internet Service Provider [ISP] gave to you)
Both puters should have the same subnet address, but diff IP address.
Ps. If you use one puter with Win2000 as Server/Gateway/Firewall for the second puter to log on then both puters could logon to the Internet on one IP address.