Multiple IOS Devices

I have an Iphone5 and an Ipad Air that are Synced on the cloud. I am getting my 10 year old son an Ipad4 for Christmas. Should I make him his own apple account or do I put his hardware under my account? If I do that I assume that I can set it up so he doesn't get my photostream and all my apps automatically loaded on his machine?

I also have a PC with ITunes on it for my phone (I have not hooked my Air into it yet but assume it can happen). Do I put his Ipad on the same Itunes account on that PC or do I put a second installation of Itunes. How would he build his own music library?

Sorry for what are probably very basic questions, just not sure how it all plays together.

Thanks.

Dan