I'm looking for some advice on the kind of specs I need in a home server. I'm new to the whole building a computer thing so any and advice would be appreciated.

What I'm going to use it for: to back up my other computers (with some kind of network attached storage? My wife does photography so she fills up her computers hard drive frequently), to stream movies from something like Netflix to my tv, and possible a tv tuner.

I have a couple of old laptops that I think I can scavenge most of the parts off of besides the hard drives so I'm not really thinking about budget right now and from what I've researched it shouldn't be too expensive besides the hard drives anyway.