andybyrd:
First - are all pixels the same size.
On a given chip, the pixels are the same size. But different models of camera have different chips and the array (pixels x pixels) may be different, as well as the individual pixel sizes. In addition, some pixels are square and some are rectangular.
Second - is the size they say 3048x2014 mean that many pixels wide and high.
Yes, that is called the array size. In the example you mentioned, many folks call that a 6-megapixel chip because it is approximately 6 million pixels in all.
Third - is it the more pixels the better.
Generally yes, expecially for field of view, but not always. For example, a 6-megapixel 35mm-format DSLR is not generally as good for planetary imaging as is a 1.5-megapixel Webcam.
Forth - the chip thats the glass thing at the end of the camera that goes in the focuser.
Yes, if you look down into the front of the camera you will see the chip sitting in there. That is the end of the camera that goes in the focuser. We call it the "business end" ... LOL.
Last- are all the pixels in the chip.
Yes. The chip is the camera's "sensor" -- equivalent to the film in a 35mm camera. Some chips are "compound", meaning they have a sensor area for imaging and separate areas (sometimes for guiding or other purposes).
Some chips are "masked", meaning one or more rows of pixels may be "turned off" because they have "dead" pixels.
Most, if not all (I haven't kept current on the chip specs), also have a "readout" area that is essentially an array of pixels that are masked off from light input but "hold" the charges that are read out from the imaging portion of the chip ... it is a "memory register", in effect.
Take a look at Jay's Web site: www.allaboutastro.com for more info on CCD imaging.