To be able to preserve vegetable's flavor and texture, you will need to blanch most of them before freezing.
WHAT IS BLANCHING?
Blanching is quick boiling then removing vegetables with a slotted spoon and placing in an ice bath, which is a bowl of ice water. This stops the cooking process because you don't want to cook the vegetables too long.
Each vegetable has a different cooking time so you will need to blanch them separately. I found this handy chart for reference. at the National Center for Home Food Preservation.
You can store in freezer safe containers, freezer bags or vacuum sealed bags.
To make dinner even faster I stored carrots, celery and onions together as they form a base, mirepoix, to a lot of my winter dishes.
I also froze the vegetables in smaller quantities. I packaged in 2 serving sizes to make it easier to simply add to make a dinner for the night and the next.
While you may still loose a bit of flavor in freezing vegetables, it's not drastic as long as you enjoy them within a few months. The benefit of convenience far outweighs any flavor lost!
When I want to use, I'll either place the bag of frozen vegetables out as soon as I get home or I'll take out that morning to dethaw in the fridge.
How to freeze vegetables that need to be blanched:
1. Bring water to a boil.
2. Add vegetables.
3. Bring water back to a boil.
4. Time it.
5. Once time is done transfer vegetables with a slotted spoon to a bowl of ice water.
6. Let vegetables sit in ice bath the same amount of time they took to boil.
7. Place vegetables in a colander air dry completely or finish off placing them on paper towels to dry.
8. Place vegetables in labeled freezer safe containers.