Can we clear up the F-stop business..
F-stop is the size of the hole allowing light through, this also affects the focal length of the shot you are about to take. So an F5.6 has a big hole and low depth of field in comparison to F22 which has a smaller hole but a better depth of field or the distance 1/3 in front, 2/3 behind the subject that is in focus.
If you imagine a correct exposure is the relationship between the shutter speed and the aperture, therefore if you have a big hole, it lets more light through, so you need to expose for less time. A smaller hole will take longer to let the same amount of light through...
What you can do is bracket exposures, so if your camera says that a correct exposure for a scene is F22 at 1/100th you can go F22 at 1/250th and F22 at 1/60th, which will overexpose and underexpose the images, but will sometimes yield better results than a "correctly" exposed image.
So, if you want lots of detail you run with a higher F stop (which is actually a smaller hole) and if you want to focus on key areas, you run a lower F stop. Just remember to play and have fun
