F Stops and Aperture

http://www.picturecorrect.com/tips/how-to-use-aperture-and-f-stops-in-photography/

Here is a great bank of information, tutorials and tips which I have found useful when learning about aperture and shutter speed; getting to grips with the concept can be difficult to start with, but this website breaks down the stages into manageable chunks so the idea is simple to understand. 

The section about what each of the numbers mean and how they can be used is helpful and can support any photography work that is being developed. Once you have the basics then you can  build upon these techniques to begin to make something creative and unique. Apply the techniques is the fun part where you can free motion, capture light and blur images into one, just by using aperture and shutter speed.

There differences between large and small apertures and they both can give very different effects when they are used in digital photograpghy.
Large Apertures are useful for portrait photography, capturing the face of the person or subject and blurring the background to stop detraction from the subject in the foreground.
Small Apertures are great for landscapes to keep a vast amount of space in focused which creates a greater depth of field.

Take a look and see what you can find!