Using old tower

I am purchasing a new Intel Core 2 Quad Processor system. I wish to keep and use my old Dell Dimension 8200 tower with extra hard drives, optical drives and 1.44 floppy drive for storage and whatever. My new machine has Windows Vista Home Premium. The old machine has Windows XP SE2. My home network has three computers wireless and wired.

Where can I learn how to set up and utilize this older tower on my home network? Do I need to leave a full operating system on it? What else do I need to know to make this work efficiently?

I am guessing the old tower would be a “server.” I’m a neophyte when it comes to these matters. All help including the very basics would be much appreciated.