I believe it's cheaper to buy already frozen veggies. The only veggies I freeze are peeled garlic and crushed fresh tomatoes. I keep the garlic in a jar and the tomatoes in ziploc bags. They both freeze beautifully. I love frozen peas and buy them all the time but it would be much more expensive to buy them fresh and then freeze. Corn also freezes well. Carrots are not so good frozen in my opinion, neither are mushrooms. I would not freeze fresh broccoli or cauliflower but if you do make sure to blanch them first.
Start here http://nchfp.uga.edu/how/freeze.html I blanch and freeze a lot of garden produce. Blanching times depend on what it is so go by the guide. I vacuum bag mine and have had 3 year old veg that still tasted fresh picked.