In the hearth of the city, the region of Harbiye. 10 min walking distance to Taksim and Osmanbey. Nişantaşı is 15 min walking distance. There is always buses on the street to historical places also metro station is 10 min by walk so you have lots of oppurtunities to see the city in a short time.
I am easygoing and compatible person. You should feel free yourself at my place and also I will be there to help you about the city. Have a good trip !