Oats are never sold with the hull on for eating, so look for "oat groats", their least-processed form which can be used in the same ways you would use wheat berries. A great source of protein, fiber, vitamins, and minerals, oats have been proven to help reduce cholesterol levels and make a great healthy breakfast that will keep you satisfied until lunch. Steel cut oats are whole oats which have simply been roughly cut while old-fashioned and quick-cooking oats have been steamed a bit and flattened; for nutrition (and some would say texture), steel cut wins out. Instant oatmeal has been rolled very thin and is partially cooked.
Because of their relatively high fat content, oats should be stored away from any heat or damp in an airtight container and they should still generally only be kept around three months.
In addition to porridge, oats can be used for stuffing, added to baked goods, or cooked whole and added to grain salads.