Installing speakers around the house??

My roommates and I want to put some speakers up around the house for our music instead of having to use just our computers; they aren't loud enough. What's the best way to go about this? We were thinking about putting small speakers, in a few corners with an input to plug into a laptop or an ipod.

Do we need a subwoofer or anything else? What kinda speakers should we look for and how do we go about doing this?

Thanks!!

Jamie