This used to be a hard thing to accomplish. I would copy my entire iTunes folder, complete with XML Library files to another drive for backup, then put them back on the new computer careful to put them back in the same exact location they were before. This worked, but it was tedious. The last time I reloaded my MacBook I noticed a new feature in iTunes.
I’m not sure when it appeared, but in the File menu there is an option which says “Back Up to Disc…” When you click this you are presented with a dialog window:
Insert a blank disc (CD or DVD, I assume) and click “Back Up”. iTunes will then save everything to your disc(s)—including playlists, play counts, podcasts, and videos.
Restoring a Library
To restore a library, simply insert your iTunes backup disk while iTunes is running and iTunes takes care of the rest. Please note you will have to authorize the computer to play anything purchased from the iTunes Store.