Most freezer meals should be kept for no more than 3 months. By using the foodsaver you can extend that time by up to 2 years (according to the manufacturer).
An old trick Shelley learned in her serving days is label, date, and rotate. Date foods when you buy them and rotate accordingly. Always use the oldest first. Foods stored for longer than recommended or beyond date on the package may change quality, color and flavor.
Another tip is to inventory your freezer. Keep a list on the outside of the freezer door and when you use an item mark if off the inventory. This is also nice in menu planning because you can look at the list and plan your menu accordingly. Read this post on monthly menu planning.
Read more of the how to freezer cook series.