KirstyWorm - This might sound a bit too obvious, but "learn the basics" - starting with 'The Triangle' - how Aperture, Shutter Speed and ISO - affect and create images. Very neatly described and shown with diagrams and images - plenty of detail, but easy to understand - under "Understanding Camera Exposure: Aperture, ISO & Shutter Speed", in the "Cambridge in Colour" Site's free Tutorials.
They have a long list of Tutorials from the Basics to Advanced - and you can of course find and use the parts you need at any time in any order....
Ref: - http://www.cambridgeincolour.com/learn- ... ncepts.htm
(the List of topics)
Ref: - http://www.cambridgeincolour.com/tutori ... posure.htm
(the Exposure Triangle)
Start of the List Page:How Your Camera Works
Understanding Digital Camera Sensors
Understanding Camera Exposure: Aperture, ISO & Shutter Speed (You might look here, first.)
Understanding Camera Metering
Understanding Depth of Field
Understanding Camera Lenses: Focal Length & Aperture
Understanding White Balance
Understanding Camera Autofocus
There are of course many, many sites offering Guides, Lessons, and Tutes - but as a 'get-you-going' - until a user knows what type of photography they'll be concentrating on - Cambridge is about the best out there.
If you want a book - "Understanding Exposure"
by Bryan Petersen, is excellent. Be sure to get the Revised Edition, which concentrates on Digital Photography.
Another is "Understanding Photography - Field Guide
", by Bryan Petersen. If you wanted just one book to put in your camera-bag and take out with you - this is a pretty good choice.....