Just upgraded to Mountain Lion. I'm contemplating setting up iCloud for the first time on my Macbook Pro and iPhone 5. This may sound stupid, but I'm a little worried that if I go wrong at some point during the setup, I'll lose some of my data. For example, I have a pretty large iTunes library. I've heard countless stories of people choosing wrong options and deleting all their music etc. What I'm asking is, is there anything I should know about before setting up iCloud? Or is it so simple even I could manage it without losing any data?