Milehigh,
What you will need on your dial-up server depends on what you plan to do with it. One of the simplest things to try is to make files available for File Transfer Protocol (FTP). This will allow you or other authorized users to copy files from, and optionally to, your server. Go to tucows.com and download yourself a copy of G6 FTP server. But be patient, shareware is not necessarily the easiest stuff to understand and get working. But it does work, I can testify first-hand on that, and it has some nice features like individual account authorization, quotas and give/take proportioning so you can get a certain amount of good stuff back for your efforts!
You can also buy a copy of PCanywhere to allow to you log into your dial-up server as though you were sitting at the monitor screen and keyboard, and actually run programs on it, and access other devices on your LAN. I've used ProComm Plus, but I wouldn't recommend it since I don't think it being supported anymore. Quarterdeck sold out and the development team quit at version 4.5 back 2-3 years ago.
If you actually want to provide web page content, you will have to get a specific piece of software for that purpose. I think Apache was supposed to be available for Win98, but I've never tried it or anything like it. Actually, Win98 has that built in, doesn't it?
Maybe most of this stuff is already in Windows 98, and you don't really have to do any of this!!! But my bet is you'll get better security and features with commercial software add-ons.
This may not have helped you a bit, but I've already typed it in, so I'll post it anyway... good luck.