Shoot Auto mode when you just want to take a picture and let the camera do all the thinking and adjustments of settings to best capture the scene. This is "Point and Shoot" at it's best. In Auto mode, the camera smartly detects what you're shooting and adjusts aperture, shutter, and iso values to accommodate. Most new users will start with this Mode.
P (Program Mode)
Program mode allows you one level of control above Auto Mode. You decide how bright or darker you want to capture, the camera adjusts everything else. On the PowerShot S95 and G12, P Mode lets you control exposure compensation whilst the camera adjusts all other values. New users wanting to advance their skills should progress to using this mode after getting a better feel of their new cameras in Auto mode.
TV (Shutter Priority Mode)
Shoot Shutter Priority Mode when you want to control shutter speeds whilst the camera controls everything else. Now why would you want to do this? Controlling shutter speeds allows you to control the amount of motion blur in images caused with fast moving subjects or from hand-shake in low light. Want to shoot kids running around? Shoot at high shutter speeds - 1/500 or more. High shutter speeds will freeze the subjects in their actions. Want to shoot funky steaks of traffic lights with moving cars at night? Shoot at slow shutter speeds.
AV (Aperture Priority Mode)
Shoot Aperture Priority Mode when you want to control aperture values whilst the camera controls everything else. Now why would you want to do this too? Controlling aperture values allows you to control the amount of light coming through the lens and most importantly, the depth of field in your images.
At a wide aperture value like F/2.0, there's a shallower depth of field resulting in sharp subjects and less sharp/softer foregrounds and backgrounds. Shoot around F/2.0 aperture values for pleasant portraits of people. F/2.0 allows more light into the lens too making it ideal for shooting in low light situations.
Closing the aperture value down to F/11 creates deeper depth of field resulting in more sharpness across the image. Shoot around F/11 for beautiful, sharp landscape pictures. F/11 also limits the light coming through the lens making it ideal for bright sunny days.
M (Manual Mode)
Manual Mode is the ultimate mode for control freaks and professionals. In Manual Mode, the camera is a tool, and you it's master. You control every setting - aperture, shutter speed, and ISO. Shoot Manual Mode when you have shot all other modes and understand the basic principles of photography. With Manual Mode you shoot pictures exactly the way you want them.
C (Custom Mode)
Custom Mode is a mode option that lets you create a custom set of shooting options that best suites your shooting style and preference. Adjust all settings to your liking then press 'Save Settings' under menu options. Your adjusted settings will now be available when you shoot on C (Custom Mode).
SCN (Scene Mode)
Shoot in SCN (Scene) Mode to use the PowerShot S95 and G12's smart-Auto modes and special effect modes like High Dynamic Range, Miniature, Fish-eye and Nostalgic Effects. Other modes include Underwater, Beach, Color Swap, Color Accent, Poster Effect, Super Vivid, Smart Shutter, Kids&Pets, Landscape, Portrait, Fireworks, Snow, and Foliage.
LOW LIGHT Mode (Candle Icon)
Shoot in Low Light mode in extreme low light conditions. In Low Light mode, the camera achieves an extended ISO range from ISO 320 to ISO 12800, capturing images at 2.5MP resolution. Manual control of ISO settings and white balance in Low Light mode also provide greater control over shots taken in darker conditions, allowing you to accurately capture the ambience of a dimly-lit environment exactly as you see it.
Video Mode (Video Camera Icon)
Video Mode is what it is - Video. Shoot brilliant Hi-definition video with the new PowerShot HD movie with stereo sound recording capability.
Hope this quick guide helps! Keep shooting!