Exposure, can't get my head around it.

[AnyDream]

I think in reality most photographers learn by trial and error, much easier these days with a digi camera where you can play with the settings and instantly see how that changes the picture.

[Alan]

I will assume that you are talking about the F Stop as this usually causes most confusion.
The lower the F number the more light you are letting into your camera. Try to think of your F Stop as a set of venetian blinds. When the blinds are open you can only see the edge of them and they let lots light in the room (small amount of blind visible = small F number). When you start to close the blinds you can see more of them and the amount of light coming into the room is reduced (Large amount of blind visible = large F number).

[UntoldAngel]

I like Alan's explanation very good for the beginner... I remember Big number = Little light, Little number = Big light... don't quite know why it works for me but it does

Also, the longer you expose something, the more light you will let in which is why if shooting at night the shutter speed will become slower to allow for more light to come in

[YoYo]

Plus depending on the light of where you are taking the pic, you would change the numbers accordingly. I was taught to take pics not when it's too bright, but a bit overcast and in the shade.....You dont' want squinty eyes from the clouds, and you don't want too much light because it's the overexposed....and that is just the natural light.