How to sync my iPhone to my computer?

I just got an iPhone 4s & I plug it in to my mac and it says "The iPhone can't be used because it requires iTunes version 10.6.3 or later. Go to www.itunes.com to download the latest version of iTunes." when i go to iTunes.com and push download iTunes 11 it tries to make a whole new account and stuff. I just want to update mine! What am i doing wrong or how can i do it another way

You are required to put an email address whenever you download it. It asks you to sign in when you open it. If it doesn't, then go to the settings and do so.