The fall garden is a time for great bounty. That sounds very romantic when actually it can be a bit overwhelming. Even if you don't grow your own garden, even what is available at the farmer's market shows a distinct change in what's available. Gone are many of the more delicate crops, and the hardy winter roots are in abundance. It's time to buy plenty of root vegetables and store them far into the winter. I always recommend starting with a vegetable that you know the family will eat plenty of. No matter how well vegetables are stored, it is important to find something you will use all the time and have reason to check often. Especially with potatoes, since it only takes one to spoil the whole bin of them. A tip for the farmer's market, if you ask your favorite vendor for a larger quantity of what you want to store, they will often accommodate you the next time they are at the market.
You can easily store many root vegetables if you have a cellar and a bit of know how. Check out how P. Allen Smith recommends storing potatoes.
If you don't have a cellar or other creative place to store potatoes, you can always Can them. I (Amy) am a believer that we all don't need to have 100 different foods, we just need to know how to prepare a small number of local foods, 100 different ways. Canning potatoes is very simple. If you are an experienced Canner, or want to find out how to do it, here is a great video that explains how to do it:
Finally, you could always dehydrate your potatoes. This is much easier than you think. Here are the directions to dehydrate your potatoes, reducing the amount of cook time they take and of course reducing the size of storage needed to keep a large quantity.
By using all three of these techniques, you will be able to store enough potatoes for your pantry to last all winter long. It's a great way to save money, because you can buy potatoes in season when they are the reasonable.