It should be possible to get yourself on the way to building a strong fortress with well-planned, basics-only documentation and tutorials explaining the principles and philosophy of gameplay (and making users aware of problematic bugs), of the kind found in
Dungeon Crawl Stone Soup. Unfortunately, to the best of my knowledge, such a tutorial does not exist. The in-game documentation is insufficient (though of course you should read it anyway), and the tutorials pinned at the top of the forum spoil some significant content and are not generally concerned with letting viewers figure things out for themselves to whatever extent it may be possible. I have some ideas about how it should be done, but any tutorial I would make would be obsolete due to my having played Fortress Mode only in versions prior to version 0.34 which came out in February.
If you are concerned about spoilers and using your noggin to the max, I would recommend against reading the forums and wiki except when absolutely necessary. Instead, if you have a question about how something works, ask here, and explain that you only want the gentle basics. Many things are intuitive and can be picked up through use, but many other things are fiddly enough in the details that figuring out how they work purely by experimentation would be painful. Mining, foraging, and stockpiling are examples of the former; stairs, ramps, schedules, and archery practice are examples of the latter, which many people here will be able to help with.
Finally, to start you off, two pieces of information would have helped me greatly when I was just starting. For one, the game world is three-dimensional, and perhaps the two most important keys are < and > (SHIFT plus , and .), because they show you different heights and depths of the world, respectively. For another, you should investigate the "workshops" and "furnaces" sub-menus of the [b

]uilding menu sooner rather than later; the structures listed there will open the way to building most of the rest of the items on that menu.
Finally,
a "plump helmet" is an edible mushroom and a staple of the dwarven diet, not a piece of armor.