I purchased a bagful of both from Costco and got to work on the onions slicing off both ends and peeling off the skins. Because of their size, I quarter them.
I love my "AS SEEN ON TV" Vidalia Chop Wizard. This thing is AWESOME! I paid $19.99 for it at Target, a bit much I know, but it is so worth it to me! And it comes with two blade sizes which is great and is dishwasher safe.
The last step is packaging up those chopped onions into freezer bags and off to the freezer they go.
Next on the chopping board is celery.Other items I always store in my freezer: Shredded cheese, sliced cheese, 2% milk, bacon, cream cheese, bread, chicken, meat, fish, and anything else that will freeze goes in.
It's what works for me.