The first thing I would not do is use the network wizard provided with XP.

Things to check:
1) Check your Network Properties and see what is listed there
2) Check the Workgroup name assigned to all the PCs, they should be the same
3) Enable file and print sharing on the 98 machine
4) Set some resource(file or folder) to be shared
5) Check your NICs for flashing lights when on
6) Check your IP and Subnet numbers(they should be in the same range)