Vegasears is right. If your Mac was built anytime in the last few years it will have both USB and Firewire ports built in.
If your external hard drive has either of those interfaces, you can simply plug it into the Mac using the appropriate cable and it should mount on the desktop and also be visible in a Finder window, even if the drive is formatted for a PC rather than a Mac.
You then have the choice of using iTunes to import the music files or you can simply drag the files from the external hard drive to the internal drive of your Mac to transfer them.
iTunes directly supports these file formats: MP3, AIFF, WAV, MPEG-4, AAC, and Apple Lossless. If you ripped the files into some other format you will need either a plug-in for iTunes or an application to convert them.
If your external hard drive has either of those interfaces, you can simply plug it into the Mac using the appropriate cable and it should mount on the desktop and also be visible in a Finder window, even if the drive is formatted for a PC rather than a Mac.
You then have the choice of using iTunes to import the music files or you can simply drag the files from the external hard drive to the internal drive of your Mac to transfer them.
iTunes directly supports these file formats: MP3, AIFF, WAV, MPEG-4, AAC, and Apple Lossless. If you ripped the files into some other format you will need either a plug-in for iTunes or an application to convert them.