What is the best way to transfer my itunes from my old macbook to my new macbook air,keeping all the playlists etc i have.
To have EVERYTHING as it is Now...
From your OLD computer...
Copy your ENTIRE iTunes FOLDER to an External Drive... and then from the External Drive to your New Computer..
Full Details Here > http://support.apple.com/kb/HT1751
An Added Bonus is that you will have a Backup of iTunes.