Like all tomato freezing and canning, this will yield the best results with paste tomatoes rather than the much juicier slicers or the too-fussy-to-handle cherry tomatoes. (Both of those work well in salsa or dried.)
I have come to the conclusion that it is best to peel the tomatoes, despite the extra work involve (it's not that bad) - frozen tomato skins end up tough and they inevitably peel off the chunks of tomato and float around in whatever you've cooked with them. Not a huge deal, but better to peel them before freezing.
Before peeling the tomatoes, core them and cut out any bad spots. This is far easier to do before blanching than after.
To peel tomatoes easily, bring a Dutch oven or other large pot of water to a boil. Have a large bowl of ice water ready nearby. Dunk the tomatoes for about 1 minute each in the boiling water, then lift them out with a slotted spoon and place in the bowl of ice water. (This is called blanching.) Remove from ice water, and you'll find that the skins slip right off.
|Blanched tomatoes ready to peel|
|Roasted tomatoes ready to drain and package|
When you are ready to use these tomatoes, thaw them in a bowl of warm water until you can get them out of the bag.