iPhone 4S won't connect to iPhone on MacBook after iOS6 update

I updated my iPhone 4S to iOS6 yesterday and just tried plugging it into my MacBook. It comes up that iTunes can't read my iPhone because I have to download newer version of iTunes 10.7. I downloaded 10.7 and when I tried installing it, it says I need to update my software (I have OS X 10.5.8). When I go to software updates it says my software is already up to date. So I went to Apple - Support - Downloads and downloaded OS X 10.6.8 and when I tried installing that it said I needed to have a previous 10.6 version of OS X. So now, I cannot connect my iPhone to my iTunes on my laptop because I cannot download the new iTunes because I cannot update my software. Can anyone help? PLEASE!!