If you have ipod/iphone/ipad, have a look at <http://www.islap101.com/>; (and review of it at <http://lifehacker.com/5501364/photo-tutor-teaches-basic-came.... There are actually two apps (one for shutter speed and one for aperture) - and they teach/display those concepts really well - even if I say so myself :-). There are also "recipes" for taking photos in various environments/situations - all prepared by professional photographers.