Let me clear up some of the confusion
First of all, good choice on the Barricade, it's a top-notch residential gateway (I still don't know why those things are referred to as routers, because they really aren't, but anyway.. )
The Barricade (at least the one that I played with) is configured by default to be a DHCP server for the client computers plugged into it meaning that all you need to do with your Win98 client is to plug it in and let it receive an IP address automatically. This should be the default Win98 setting. At that point, you can either use the provided SMC software or use the Barricade's web interface. I personally prefer the web interface. (And due to the plug 'n play nature of networking devices I don't believe in installing platform specific software.) The web interface is actually quite handy. All you need to do to access it is go to
http://SMC.private.IP.here in your web browser. That SMC.private.IP.here is a number like 192.168.x.x but I don't remember what it is by default. To find it, just go start -> run > winipcfg and press advanced and then look for something like DHCP server or Gateway. (I don't have a 98 box handy so I can't actually verify this.) Once you get that IP address, just plug it into your web browser and if everything up to this point was set up right, the Barricade's configuration screen should appear.
RR should provide you with some crucial info such as your IP address, DNS servers, and Internet Gateway. It is also quite possible that they will automatically assign this info in which case all you need to do is set up the Barricade to be a DHCP client. All of this is pretty well laid out once you log in to the router. I can send you some screenshots of my configuration once you start setting it up if you get stuck or something.
You mentioned something about a virtual server. Basically this allows people on the internet to access some service you are trying to provide, like FTP or HTTP. In order to do this, you would have to set up the service on one of your win98 computers and then forward the appropriate tcp ports to it via the Barricade's configuration menu.
Also, I don't think that built in printer port will work with your scanner, but it should work just fine with your printer plugged directly in. You will have to install a special printer driver on each of your computers so that you can print over the network (rather than directly to a local parallel port). You can still connect your scanner to one of your computers.
It sounds like you don't really have much that you can test out right now, but in the meantime I'd suggest reading up on the manual and CD content. It's a pretty good resource.
~bex0rs
edit: fixed a confusing sentence