Look for the Poe with Wolf Link's senses and follow the trail
The mirror of twilight is in the desert. you gain access through the mirror of twilight after defeating the boss of the desert temple.
In the sea temple.
In the first temple
Death Mountain
day fly
well it really depends on the ghost your on the first one is easy :p
It depends on which one you're finding. Try going on gamewinners.com.
you go out the door you came in from
the forest temple
It's on the map.
beat the boss
the gorons mines