No clue on Aperture, never even tried it. Amazing since my whole system at home is Apple.

External hard drives are fairly cheap now. 2-3 tb can be had well under $200. I think this is the easiest solution for you just starting.

My system is a bit more elaborate because I have a Mac Pro with four hard drives. I use Apples Airport Extreme for wifi, it syncs the apple tv, my Iphone, the wife's macbook pro and two other computers. I have a 2tb hard drive that they all share off of Airport. I have all my Raw files on the network hard drive so I can access them any where in the house. I also have them duplicated on the Mac Pro's hard drives. I have a few external hard drives I bought. Occasionally I will back all the new files up to them then store them somewhere else just for safety.