peteABK,
Sorry for the long answer, but...
I'm just limitted on the number of LAN connections to my router
If the Linux box doesn't have two network cards, then you won't save any ports on the router. Consider buying a cheap hub and some more cable.
Sorry for not being specific, but it's really up to what
you want to do. How comfortable are you with networking in general? Are you familliar with Linux in general, configuration files (httpd.conf), and such. How comfortable are you setting up more advanced networking (NAT, firewall, routing)?
would I still be looking at the ProxyPass or would it just be a dns issue?
Both :) If you are using ProxyPass, it just redirects requests to another machine. Virtual hosting allows you to run multiple DNS names from one server. When you combine the two, then you would serve two machine names from "two" computers (one is always involved). It is somewhat inelegant, requires more configuration, and not "simple".
The easiest solution (IMHO) is to have IIS hooked up to the D-link router and have the router do the port forwarding. (My second answer). What will happen is your main site will stay the same (
http://www.example.com/) and your second box will use a different port (
http://www.example.com:8080/). Just make sure to secure you windows box :) That way you are only configuring IIS and it won't depend on another machine, but hey, that's what you are trying to learn about. How is the Dlink configured now? Is it doing NAT? Do you already have a domain name that you are using?
Also would running one as DNS speed my internet up a little or would it be basically pointless?
Do you want to use the DNS locally? It can speed some things up, and it lets you setup multiple computers on your network easier. Serving up your own domain to the internet will be a bit more complex. Personally, I would setup a DNS server on your redhat box, but don't let the internet access your DNS service (port 53). Just serve to your other machines. Then use one of the "free" DNS server companies (I've used
http://www.zoneedit.com) to serve DNS over the internet.
If you have any more questions, you may want to describe how you have everything networked together. The more specific your questions, the more specific we can be.
Have fun,
chris