How to get Dolmabahce Palace?
Dolmabahçe Palace is between Beşiktaş and Kabataş, where you can get easily.
If you are staying at a hotel in Sultanahmet, get on a tram and get off in the last station; Kabataş. Then walk through Bosphorus for 5 minutes, and you will see Dolmabahce Mosque, Clock tower and behind them Dolmabahçe Palace.
If you are staying at a hotel in Taksim (Beyoglu), you can walk for 15 minutes down hill to Kabataş. Or you can get on Finuculair and go Kabataş and walk through Dolmabahçe Palace.