ISO, Shutter Speed, Aperture Priority, F-Stops, 25-300mm, Exposure, 15 elements in 14 groups, white balance... What are all those things and why are they important!??! Do they all really matter for each and every shot? Should I shoot in Manual, Av, Tv, P, or Auto? Should I buy an external flash? Why do professional photographers carry a bag full of 57 lenses and filters? Machine wash or dry clean? Duct tape or superglue? Can someone explain the absolute BASICS of all this for all us noobs?!?!