Ooooh...pantries! This is my favorite! Basically, what you should have in your larder is 100% dependent on what you ACTUALLY cook and eat. I know that seems obvious but people get sucked into buying stuff they will never really eat because its a good price or they got a sample at costco or whatever. In my pantry, I keep a lot of canned (home-canned, but only cause that's my deal) tomatoes, pasta, whole wheat flour, corn meal, oats, rice, various beans and other dry goods. I keep quite a few Asian-type seasonings on hand because we do a lot of curries, stir-fries, etc. for fast meals. I always have yeast because we make our own bread and if you stick one of those huge containers of yeast from Costco in the fridge it'll last for years and is way more cost effective than the little one-gram foil pouches. We buy meat in bulk and have it in the freezer. If you have a big freezer this is a good way to take advantage of food savings, but I definitely spend more on electricity because I have quite a few boxes that keep things cold in my house, so assess the actual benefit for your family to stockpiling. (In our case we buy from wholesalers and farmers, so when we get meat we get A LOT of meat and the freezer setup is good for us.) I dry and freeze a lot of fruit in the summer, so that is also on hand for us. Frozen fruit is great for smoothies, desserts, mock blender ice cream and just to eat out of hand and my kids like it a lot.
The short answer to "What should I keep on hand?" is - food you will eat, and that is flexible for multiple applications. That's why I love canned tomatoes - in the winter they go into just about everything.