well make sure your itunes is up to date, check how much hardrive space you have before downloading (my computer>default drive c> details space>) after your sure you have enough space create an itunes account, and connect a credit to it or gift card there will be a download link on every page many time over, each one is set up with a different item, once you download you will see a link in the right hand side of itunes click on it and it shows progress, once complete you can play in in the itunes theater this is a basic run through explain to me specifically whats your problem and id be glade to go into greater depth on the issue http://www.apple.com/itunes/download/ -latest itunes http://docs.info.apple.com/article.html?artnum=303635#section4 - these are some in depth guides on everything itunes
