Brand new to Mac, and need to do a couple things: I have an external hard drive that's been converted (not formatted) to NTFS. This drive has all my mp3 files on it. I'd like to copy the files to my new iMac, then reformat the external drive and use as the Mac's backup via Time Machine. Will it be just that easy to do? What format should I use when I reformat? Any problems I haven't considered? If anyone has a step-by-step guide for me it would save my going back to the Apple Store and have them do it. Thanks in advance.