I am going to uninstall my OS but before I do I need some help

I am going to uninstall my OS from my 320gb HDD.

Instead of backing it up to some online site couldn't I just copy all that data and put it on my 2TB HDD that I have in my computer?

Then once that's done I plan on delete everything on my 320gb HDD and re installing my OS onto my 120gb SSD. So in the end I should have my OS on my SSD and all my data on my 2TB HDD. Is there anything you see wrong with this or any other way I should go about this?

Oh and here is a picture of my storage devices just in case anyone got confused when I was explaining what I had: http://i.imgur.com/mfGSl.jpg