There are about a gazillion ways to preserve tomatoes for winter. In the past, I've canned them whole, diced, crushed, as tomato sauce, pizza sauce, and salsa. I've also frozen them most of those ways.
Each option has it's ups and downs. Canning is fantastic because it doesn't require any freezer space, and you can stash jars just about anywhere. And if you happen to lose power, your canned goods won't mind. However, the process of canning - boiling tomatoes for nearly an hour - seriously depletes the nutritional value of the fruit. Freezing is just the opposite - it maintains nutritional integrity, but requires space in the freezer and electricity. I do a fair amount of both. I decided to freeze today's tomatoes, because quite frankly, it's too hot to have a ginormous pot of boiling water on my stove for a couple of hours.
Freezing tomatoes is a lot quicker than canning too - especially if you're lazy, like me. Here's a secret: you don't really have to peel tomatoes to freeze them, especially if you're dicing them. Yes, there will be tiny bits of tomato skins in whatever you're cooking, but they aren't really much of a problem.
When I freeze tomatoes, I just core them, cut out any bad spots, and dice them up. Then I freeze them in 2-cup portions in plastic bags. Each little baggie equals the same as a can of diced tomatoes.
(I realize freezing anything in plastic is probably not the healthiest option. But they fit so much nicer in the freezer this way - see?)
When it comes time to use them, you can just toss them into whatever you're fixing (thawed, usually). If you need tomato sauce, put the thawed tomatoes into the blender and whir until smooth. It took about half an hour for me to get these 10 cups into the freezer - totally worth it for the pleasure of vine-ripened organic tomatoes in the middle of winter!