Back up

I often-used i-tunes which is music computer soft. I installed all CDs I had and I often listened "Poscast" of English which like internet radio so I installed "Podcast". It has already installed 9.31GB. I don't want to lose it so I tried to backup all data.

I have done backup about 1 year ago. It took 2 DVDs but in this time I tried to backup that I installed after I backup 1 year ago, even it took 3 DVDs. It's so huge data.

I should backup some times.