I am not Turkish, but I have been to Istanbul a number of times. Of course you will want to see the Agia Sophia, Blue Mosque, Hippodrome, Topkapi Palace, the Grand Bazaar and the spice bazaar, Dolmabahce Palace, perhaps take in a visit to a hamam (I have been to a few, but only remember the name of the Cemberlitas Hamam which was quite nice, but I am sure the locals will tell you it can be touristy). I love to have nargile while there and since I am usually there off the boat, I head over to Tophane where you will find a dozen or so nargile bars. From there, you can easily walk toward the Galata Tower for excellent views and a very cool old neighborhood. From there, walk up hill and until it levels out along Istiklal Avenue, a pedestrian street that takes you along toward Taksim Square. Turn left or right off Istiklal and you can find some really cool neighborhoods for good food, bars, night life, etc. For an off the path, historical and photogenic half day, spend some time walking along the Theodosian walls (
Walls of Constantinople - Wikipedia, the free encyclopedia )
Have fun!
Jason