Originally the consumption of oats was only intended for livestock, specifically horses. Through the years we have been able to accept them as an amazing nutritious food that is extremely versatile. Oats is a generic term and I wanted to attempt to clarify some of the different kinds of oatmeal you can expect to see at your local grocer.
Groats- the first step of oatmeal, can also be called kasha (although the term kasha can be buckwheat, barley, or wheat groats). They are a long cooking product and my approach to them is more like my bean and legume approach. I have pretty minimal experience cooking them, but have recently acquired a pound for experimentation at home.
Steel Cut Oats- Like the name suggests these are groats that have been cut. In my opinion they are the far superior option for breakfast. One of my favorite meals of all time is steel cuts with dried cherries, cream, and brown sugar, or in season, the exact same dish sans cherries with slices of peaches on top. Something so pleasant about it simplicity. They take some time, but are far more healthy than the quicker cooking oat forms. I like a water ratio of about 4 times the amount of steel cuts, and about 45 minutes of cook time on medium-ish heat. They can be reheated as well so for a quick breakfast option I will cook more than I need and cool and then reheat for the next few mornings. In some research for this post i attempted a over night crock pot recipe that I heard on a TV show recently. The steel cuts caramelized and took a great sweet flavor, with dark color to match. My boys wouldn't eat them though. They are usually available bulk at the grocery store, or sometimes in tins labeled Irish, or Scottish oats. Try them with any array of dried fruit, or fresh fruits or berries and you wont be disappointed. In fact I bet you never go back to the other stuff.
Rolled Oats- If you were to take the steel cut oats and individually roll them flat you would have the most popular form of oats. I do understand the appeal- quick cooking, versatile, and for the most part they are what people expect when you say "oatmeal". They are still very high in fiber, and in baking they are the option to use as steel cuts usually wont cook thoroughly in most applications I can think of.
Quick oats/Instant oats- these are parboiled, or blanched (and sometimes cut) rolled oats. I hate them. I hate them for their lack of nutrients that have been lost in the precooking process, I hate them for their easiness, and for their disrespect to all the other forms of oats. These are the oats that cook in just a few minutes, sometimes even in the microwave, or even with just the addition of boiling water. They lack any of the flavor, or color of the better forms of oatmeal. If I had a horse I wouldn't feed them to it.
Serving ideas are a fight at my house. My wife grew up eating them with crackers, so while I cant think of many things that gross me out more than that, in my absence for breakfast at my home my boys have decided that is how they are going to eat them. I had never heard of such a thing before I met her, but apparently it isn't that odd, as we get people requesting them at the restaurant sometimes. Like i mentioned before some cream or milk, dried or fresh fruit, some brown sugar, and of course a pinch of salt is how I take mine. Hold the crackers.