Home server network ideas

My wife and I mostly use computers for internet and media... BIG media. She and I both are music freaks, so the two of us together have about 200g of music. She is also starting this sorta cottage industry of editing video, so at any given time there are a few hundred gig of video around. So, between the two of us, we have three laptops and one desktop. I want to sorta consolidate. I was thinking of keeping the two good laptops and then doing a server kinda setup with massive storage; have it hold all the files and help keep things organized.

I don't know the terminology well, and I can only vaguely describe what I want, but I'll try. The laptops have sufficient HD space to hold commonly-used things like programs and some photos. So I want to have a huge server that can store all the media and stuff, then I can plug into it when I'm home. I'm sure its possible, I just don't know much about it.

-Can someone give me kind of a rundown of what I might need?
-Can I use my desktop case/board as the basis of the server, or will I need more? Its an ASUS board, 3.3 ghz intel, it was top of the line 3 years ago.
-Can my connection to the server be wireless? Like, can I use it as an external hard drive wirelessly, or do I have to be physically hard-wired?
-What operating system should be on the server? Should I keep a keyboard and monitor with it, or can I access it with the laptops for maintenance?

Basically I want to be able for my wife and I to have laptops that can access a terabyte or six of media, edit locally, store remotely, and have the server handle all of the other stuff like printer, internet, etc.