Basics: The tools you'll need to take better pictures, be they professional or just candid shots, I hope I can do something to help you out.
Glossary: (if more than one applicable definition, the bold one is that will more likely be used to critique)
the opening on a lens through which light passes.
Depth of Field:
the area of acceptable focus.
the total amount of light received by a photosensitive surface or an area of such a surface, expressed as the product of the degree of illumination and the period of illumination.
Film Speed (ASA or ISO):
This is how quickly your medium (film or digital) can absorb light. The higher the number, the faster it will absorb.
Common Speeds: 100, 200, 400, 800.
High Speeds: 800, 1600, 3200
You may also find oddly numbered ones, 320, 640, 1280, but the same principle applies.
the amount of magnification (or more commonly, Zoom) *this is determined by the distance of the rear glass of the lens from the focal plane. not basic, but it's a nifty tidbit to know.
Point and Shoot:
refers to camers that do not require aperture or shutter speed settings.
the length of time a shutter is opened to expose film.
Single Lens Reflex (SLR):
cameras using mirrors to reflect an image to the eye, commonly allow more control over an image using aperture and shutter speed.
a tool with 3 legs commonly used with a camera to ensure steady shots. Often used for shots where the shutter is open for extended periods of time.
Using a Nikon D50 as an example -
Most newer cameras, SLR or not will have the Mode Setting Dial and all cameras will have a shutter release (when you tell strangers how to use your camera they point and go "Is this the button I press?" and you say "yes.")
Focal Length is measured in mm. In this image, it has been set to 35.
Shutter speed is measured in seconds. Or rather, fractions of a second.
This is set to 1/4000th of a second. This is what is referred to as a fast shutter speed. If the speed were set for 1 second or longer, the number would be followed by quotation marks. I.E. 5" would be 5 seconds, where as 5 would be 1/5th of a second.
Aperture - Common apertures are 4, 5.6, 8, 11, 16, 22. Numbers may be lower or higher. 4 is usually wide open (allows more light), while 22 is nearly closed (allows less light).
The Mode setting Button: Auto is automatic. P is program. S is Shutter Priority. A is Aperture Priority. M is manual.
I'll touch on these later.