From what I know, our instructor Anders Mouridsen has a secret trick: he listens to songs over and over very closely before ever picking up the guitar. While driving in traffic, etc. I think he tries to get the entire thing memorized in his head (the leads, etc.) and can sing along with every note. I agree that's a very good way to internalize a song. Because if you don't even really know how the song goes, it'll be that much harder.

There was some great guitarist (I think it was Steve Vai or Joe Satriani) who said that if you can hear it clearly in your head you can teach it to yourself.

That's why Anders always says to watch through the Performance video a few times before trying to play along.

-Carl.