Accessing Data on an old Hard Drive

I'm finally getting round to sorting out a new PC, and once it is delivered, I would like to access some data on the Hard Drive in the old PC.
Mainly I just want to get my music files.
Once I have those there is nothing else I need.

Being a bit of a newb at such things, I've had a mooch around the net to try and find what I need to accomplish this, and it seems all I need is one of these:

http://www.amazon.co.uk/USB-SATA-Ada...238565&sr=8-15

to connect the Hard Drive to the new PC.
Once I've copied the files I want, that should be it? Kind of seems too easy, really.
Am I missing something obvious?

Old PC ran Win XP, most likely the new PC will use Windows 7, if that makes a difference?