I'm pretty new to the Mac world and I need to get an external hard drive. Is there anything I have to consider when purchasing one? Can I get any drive and just plug and play or will I have to do some kind of reformatting?

You can get any sort of external hard drive. They are usually plug in and transfer files, movies, etc with no problem. The only problem you will encounter is if you do not have a software program such as Microsoft Office to get the files from your computer to the external drive. You need to be able to make folders on the external drive. Don't know what O/S Macs use.

And as for formatting the external hard drive, they usually have the FAT config and not the NTSF config. This means that the defragging of the hard drive will take you longer in the end.