Thanks for the time you took to answer, however my knowledge is limited to pretty much setting up a LAN on XP OS and setting it up to be online through a "master" PC that also has XP on it.
So if you could elaborate a bit, I would be most grateful:
Would I need to set up port forwarding on Linux? If so, how? My knowledge of Linux equals almost zero.
Would I need to install Radmin Server\Set up the Account on Linux (provided it works on it) and then set up the client at home to "Connect through server"?
A few step-by-step pointers would be useful.
It really depends on how you're Linux box is set up. If everything goes through your Linux box (WAN --> Linux --> Switch --> PCs) then it is probably using IPTables as the firewall. You can configure that through the GUI if it is set up, or edit the IPTables config file. You will not have to set up RAdmin (nor, is it compatible, as far as I know) to manage the Linux box as Linux offers SSH connections through the command line and VNC as an open source option.
If your network does not pass through the Linux box on the edge of your network (WAN --> Router / Switch --> LAN), the Linux box should not need to be pre-configured unless it is being used as a proxy.