First, you need the Microsoft Client for Microsoft Networks installed. This may all work with other clients installed, either Novell or Banyan, but no guarantees. Certainly, the Primary Network Logon must be set set to Client for Microsoft Networks; there's no hope of it working any other way.
Next, you'll need an LMHOSTS file in your Windows\System directory. There should be a sample LMHOSTS files there already, under the name of LMHOSTS.SAM, but here's a copy of mine; just one line, listing the address of a domain controller.
Now you need to install the Microsoft Directory Services Client, found here. Download to your Win98 machine, double-click to install, simple.
Now you need to edit the registry to enable the appropriate authentication mode (NTLMv2). You can either edit the registry manually, following the Microsoft instructions available here, or download and double-click this REG file.
Finally, go back to your Network Control Panel and select Client for Microsoft Networks. Click Properties. Tick Logon to Windows NT Domain, and in the Windows NT Domain box, fill in ADSFU.
Reboot as prompted one more time, and you should be in.
One little caveat is this: Windows98 (and NT, methinks) will only map to the root of a share. For example, there is a machine named
ACS-Server1.ACS.SFU.CA
with a folder inside named
\DEPTS\ACS\USERS\BEER
which is my Home directory. Under Win2k, I can map this folder to a root drive letter, like U: Opening U: from My Computer puts me right inside that folder. Doing the same thing under Win98 "wakes me up" in \DEPTS, wherein I have to navigate three levels down to get to my home folder. The solution is to simply navigate there once, create a shortcut to the folder and place that shortcut on the user's desktop, after suitably naming it to something they'll remember.
Notes: