Why won't my iphone sync to itunes on mac?

I'm trying to add songs onto my new iphone 4S but the computer only charges the phone. It won't show up in itunes on my macbook pro. I couldn't find the answer from googling it so posting this question is my only hope to finding the answer. Please

" I couldn't find the answer from googling it "

What did you search for?

http://support.apple.com/.../kb/HT1386

http://www.apple.com/...e/syncing/

http://www.dummies.com/how-to/content/how-to-synchronize-your-iphone-with-your-computer0.html