In some of the museums or palaces you are not allowed to take pictures or use flash, before you go in, just check if there is a sign with a camera crossed over, which means keep you camera in your hand bags, or check them in. Also, as an universal rule you are not permitted to touch any of the artifacts displayed.
Photographing the Turkish ladies in the rural areas may offend them. The procedure is, just direct your camera towards them, if they say no, or mean it with gestures, just leave it. Some people including ladies love to be photographed, and will probably give you their address hoping to receive a copy from you.