Hi. I have a 2008 Macbook Pro that's running Mac OS version 10.5.8. I know NOTHING about external hard drives, backing up...etc. What is a good external hard drive that I should buy? I'm a novice computer user and mainly use my computers for papers, photos, Rosetta stone software and the like. I don't need the best of the best of the best but I want something trustworthy, reliable and reputable. Where do I even start to research this? If I hook this external hard drive up to my Pro, can I hook it up to my work computer (2012 Air)? Can I hook it up to a PC? How does this work?!?! THANK YOU, in advance, for your assistance!