Jon, Tutorial on here I am not sure about. Let me explain a little bit about cameras and how they work. These three things I talked about are probably the most important things to understand about cameras. The f-stop or apature is the amount of light that goes through the lens. The larger the f-stop(smaller number) the more light you let in through the lens. So a f8 lets in less light than f5.6, which is less than f4, which is less than f2.8.
Please don't ask exactly what these numbers stand for or mean because it is some complicated formula dealing with the doubling of the light let in and so forth. I don't completely understand exactly how they came up with the numbers myself.
The shutter speed is the amount of time that you allow the light to hit the sensor in your camera. Just remember that if your camera says 250 it is 1/250th of a second. This is faster/or a shorter amount of time than 1/125 and that is faster than 1/60th or 1/30th.
With a camera you control the amout of light that you let hit the sensor by these two functions. You control the amout of light that goes throuh the lens and you control for how long that amount of light comes through. These two functions generally act in a ratio together. To make a proper exposure in your camera you have a f-stop and a shutter speed. So if your proper exposure is 1/250 with a f5.6 you could achieve that same exposure with a 1/125 and f8.
So what I did was to slow the speed down by 1 stop and closed the lens by 1 stop. Less light through the lens but let in for a longer amount of time. So these two examples will give you the same exposure. Every proper exposure can be achieved in different ways, so why would you want to change it. If you want to stop the action you need a fast shutter speed. What does changing the f-stop do? It changes how much of the picture is in focus.
Lets use one of your pics as an example. You have one on your gallery where you took a pic of the arched sign but there is a white pole in front of it. The sign is in focus but the white pole is not. I would guess that it was a wide apature(low f-stop number). The larger the f-stop(smaller number) the focal distance is small and the smaller the f-stop(larger number the larger the focal distance is. Another example would be to take a picture of a car from the front. If you use a large f-stop(smaller number) only from maybe the bumber to the headlight might be in focus. As you go to a smaller f-stop(larger number) you might go from the bumper to the windshied. Go even smaller and you will get the whole car in focus.
For things like landscapes you want a small f-stop to get most all of the picture in focus. When you see pics on here where the background is severly blurred it because they used a large f-stop(smaller number).
Now lets talk about iso numbers. This number refers to film cameras but it has carried through to digital cameras. This is considered the film speed. Using an iso speed of 100 would be used for really bright sunlight. If you had a dull or very overcast day, or maybe you went to a bright inside then you might want to use 400. Very dark inside you might want to go to 800. Bear in mind that as you go to a higher iso number you will get more noise in the picture. Looks like little speckles of color in the picture. Try looking at some pics on here shot with a very high iso setting to see what I am talking about.
Most of these numbers you just need to get used to and experiment with. I am sure some of this may be confusing, I will try to answer some of your questions. Let me know what they are. Hope some of this helps. Magazines are a good place to read alot of this as they are short articles and you don't need a college degree to understand them.