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.
On the new mac I deleted the file called iTunes Library.itl, Extra's, Genius, and xml file.
Copy your old .itl file over to the new mac and start itunes by double clicking.
Everything is there instantly.
If you have another hard drive that you hookup to the laptop that holds all your music. Than make sure your preferance is what you had on the old laptop.
Works perfectly fine! Easy and took 5 mins or less.