iTunes and new laptop

Whats the best way to a)transfer an itunes account and b)be able to sync your iphone to a new computer? I've tried transferring my itunes library via a memory stick, but on my new laptop after i removed the memory stick there was a circle with an exclamation mark next to all the songs and they couldnt play? Please help

Is the music on your iPhone all legal iTunes music?

Theyre mostly cd's which were imported?

In that case I think the only way to put them on your new iTunes is to import the CDs again. You can make a backup of your iTunes library on a CD and import that, but I think that must be what you tried already with the memory stick. With the old Classic iPod you could easily transfer the music because the iPod acted like a memory chip, but with iPhones and the iPod Touch I think you can only easily transfer the music straight from the iPod if you bought the music on iTunes.

Sorry I can't be of more help!

What does it mean if there is a circle with an exclamation mark by the song title and how can i stop that from happening? Cuz i cant play any songs with that circle