In the System Control Panel (the grey icon with the lightswitch in your dock) go to Sharing, then check "Windows Sharing". You'll need to enter a password to enable this, but afterwards your home folder will appear as a share on your windows 98 network neighborhood. You might have to find the share directly by going to the Start Menu in 98, clicking on RUN, then typing "\\192.168.0.111" without the quotes, substituting the IP address of your mac for the 192.168.0.111. To get the IP address of your mac you can click on the network icon in the Control Panel.
HTH