If you want to save the blockchain and everything, shutdown bitcoin-qt first then, I would suggest just saving the folder ~/Library/Application Support/.bitcoin
then you can just put that in same spot on your new computer if it is a mac.
Thanks! I'll give this a try also If I've already backed up all files on an external HDD will my Bitcoin-Qt files be saved there as well?
I'm takin the Mac to the Genius bar to get its health checked out before I sell it. I might even ask them to clean re-boot the entire system and have it
ready for the new owner but before I go about doing all of this I want to make sure I don't lose access to my BTC.