Drive letters on a workgroup

I've just set up a few PCs on a office workgroup (win 98se and XP) and have
stumbled (tripped!)
over the problem of sharing data and how to set up a coherent set of drive
lettes across all PCs.

The problem is how to set up workgroup PCs so that one shares its data (and
uses it); the others use the data (across the workgroup); and all the
software is the same copy on all the PCs, with the implication that all the
drive letters that the software uses have to be available on all the PCs!

The PC builds are very different, so the default drive letters are all very
different.

There isn't a server as such, but one of the PC's (the oldest, win98se) is
sharing
out more data than any other, so I'll call that the "server", and the others
the "clients".

I think I need to define a set of drive letters which appear on each PC,
along with the default letters that appear because of the hardware
configuration.

I think part of the solution is to "map" a set of drives on the clients to
the drives on the "server", but how do I create the drives on the "server"
so that they are the same as those on all the other PCs?

I'm not sure that mapping a drive on the workgroup back to itself is a good
idea? Any other options?

Regards
Stephen Ford