First of all, if you want to take better photographs, you should be using the manual settings on your camera anyway. Don't care? Then imagine you woke up this morning and the back of your camera lcd was broken, including all the automatic settings. You can't buy a new camera because you don't have the money. This would leave you with no choice but to use the dreaded "M" setting. So how would one even begin to know these mysterious coded/mythical/hieroglyphical camera settings? Well if it's sunny outside, I can help.
A hard fast rule for knowing manual camera exposure settings, without any automated assistance, is the "Sunny 16 Rule." This rule essentially states, if it's a bright sunny day: set your aperture (F-stop) to 16 and your shutter speed to the reciprocal of your ISO speed.