http://www.photo-geeks.com/understanding-exposure/ Your ultimate photography cheat sheet guide. Complete with info about aperture and how it relates to depth of field, shutter speed, ISO, and exposure. All the essentials. http://www.photo-geeks.com/understanding-exposure/
What is Shutter Speed? Photography Tutorial #BACKTOBASICS
If you own a digital SLR camera and are getting comfortable with daylight shooting, then the next natural progression is capturing the night. Find inspiration from several beautiful examples of night photos, plus 10 simple-to-follow tips you can use today to get a firm grasp on night photography.