You can freeze just about anything, and it's as simple as doubling up on your recipe every time you cook. In no time at all, your freezer will be full. What you decide to freeze is entirely dependent on what you like to eat.
Soups freeze very well, so long as they do not contain potatoes or are of a cream variety. Creams tend to separate, and potatoes turn mushy. However, you can always freeze your soups without potatoes. When you decide to prepare your frozen soups, just boil a potato or two separately, and then add to your soup while it reheats.
You can freeze soups in freezer containers, but I prefer storage bags designed for the freezer. They take up much less space and stack nicely.
When preparing a casserole or lasagna, make two. Eat one now, freeze one for later. When you have leftovers of anything, simply place the item in a storage bag, date, and freeze until you have enough for a meal.
Veggies that have gone past prime, vegetable peelings, bones, shrimp shells, and other items are great for flavoring soup stocks. Again, simply freeze the items in a storage bag. When you are ready to make soup, you'll have a supply of vegetables and other necessities on hand for flavoring.
There's so much information available on freezing that it's impossible to list it all here. At the following link, you will find everything you've ever wanted to know about freezing food, along with various tips and tricks.
http://busycooks.about.com/sitesearch.htm?q=how+to+freeze+food&SUName=busycooks