Marjoram is in the mint family (like so many of our favorite herbs) and is a sub-species of oregano. It also looks very similar to oregano with woody stems and flat, rounded leaves, and the two are often confused. You can tell the difference in the smell and flavor: marjoram is floral and woodsy while oregano tends to be much more pungent and spicy.
Because its flavor is so delicate, it's best to add marjoram at the very end of cooking. We like it in salad dressings, marinades, and sauces - anything getting paired with grilled meats, beans, or grains. Sometimes we break our own "add it last" rule and use it in pot roast braises and our favorite rice and mushroom casserole, where it adds a very mellow and somewhat sweet herbal flavor.
How do you like to use marjoram in your cooking?