I had used a MacBook for a bit and then a MacMini. In both cases I bought one of these to store my music and used the FireWire interface to connect to the computer. I mapped the music software (Audirvana, JRiver, Pure Music) to this external drive and you can do the same if you want to use iTunes. A simple and cheap solution.
I have moved on to a NAS set up but find the Oyen Digital HD is a nice backup storage solution. Two are affordable and a backup is worthwhile.
http://www.amazon.com/s/?ie=UTF8&keywords=oyen+digital+minipro&tag=googhydr-20&index=aps&hvadid=23404253267&hvpos=1t1&hvexid=&hvnetw=g&hvrand=12140434102838234616&hvpone=&hvptwo=&hvqmt=e&hvdev=t&ref=pd_sl_2xtdyqre5q_e
I have moved on to a NAS set up but find the Oyen Digital HD is a nice backup storage solution. Two are affordable and a backup is worthwhile.
http://www.amazon.com/s/?ie=UTF8&keywords=oyen+digital+minipro&tag=googhydr-20&index=aps&hvadid=23404253267&hvpos=1t1&hvexid=&hvnetw=g&hvrand=12140434102838234616&hvpone=&hvptwo=&hvqmt=e&hvdev=t&ref=pd_sl_2xtdyqre5q_e