Howdy! I can help you with a few things.
First, you don't need a static if you use someone like dyndns.org as your registrar. I use them for my domain and a few others I host (all on Slackware, running Apache), and it works great.
1. Add a port forwarding entry on your Linksys router that forwards port 80 to the internal IP address of your Linux box. Share the desired directories from your W2k PCs. Use smbfs entries in your /etc/fstab file on your Linux box to mount those shares. You can mount them as shares within /var/www/htdocs, or you can mount them elsewhere and put symbolic links in /var/www/htdocs.
2. Your port forwarding entry (in the Linksys Router, go to Advanced -> Forwarding) and either the static IP or a dyndns.org will take care of this. Make sure your ISP does not block port 80, or you will have to set up an external port forwarder; dyndns provides this as well (I'm not affiliated with them, other than as a very satisfied customer).
Building Secure Servers With Linux (but it's cheaper at bookpool.com). Keep your patches up to date; that's pretty easy. Don't run any other services on that server; a single purpose (and single port exposed) server is a tougher nut to crack. Read, read, read. CERT advisories and Bugtraq are good resources.
4. Depends on what you want. Pick up "Learning the bash shell" and "Learning Perl" (probably "Learning the vi editor" as well) at the same sources.
You're right, I don't need the space.
But thank you for the offer.