Please help me with my canon G11...?

i wanted to take very good image quality, so i changed my compact camera and bought canon G11. actually i am not very knowledgeable about camera settings. i just want clear pictures. something that can capture the greeneries of the mountain in the background or the blue color of the sea and sky. please explain to me the ISOs, aperture, focal something in layman's term. i dont know what that 1/200 or 1/400 means... is that the aperture or the shutter speed? i knew a little about ISO being set in dark scenes so as to lighten the picture but gives the picture noise. and what is that f2.4 or f4.0 mean? what is the normal "f" to use in normal light conditions? sorry, i know i shouldn't have bought complicated cameras. but what can i do, i just want clear photos... thank you so much