Are your two hubs "stackable?" Do they both have uplink ports? Ultimately, you connect one hub to another with either a crossover cable (if the two ports are the same), or you use a regular cable (if the two ports are not the same -- ie and uplink port to a regular numbered port).
The problem may end up being that you are trying to setup a peer-to-peer (P2P) network with more than the recommended MS maximum of 10 peers. You may have problems with users being dropped from the network andnot being able to connect to shares on other computers. You should have a "server" with more than 10 computer stations.
To enable "sharing" you need to go to Control Panel --> Network --> and click on File and Printer Sharing button. Check off the items you which the users to share (folders and/or printers). Then right-click on the folder or printer and click on sharing.... and configure it as you want it used.
All Win98 computers may need the MS NetBEUI protocol installed for broadcasting their potentential shares and for browsing in the Network Neighborhood icon on their desktops.