This enough for you?
For foodies:
http://istanbuleats.com/
Personal recommendations would be breakfast at 'Kale' in Rumeli Hisari or 'Namli Gurme' in Karakoy.
Lunch: going to be less colourful due to Ramazan but fuck it. 'Helvetia' in Tunel/Asmali Mescit or House Cafe in Ortakoy.
Drinks: Nu pera teras on Mesrutiyet Caddesi (Mesrutiyet road near Taksim) and 360 on Istiklal caddesi for sunset cocktails. Also fish and beer on Nevizade in the evening. Or fish and wine along the Bosphorus in Bebek or Arnavutkoy. Anjelique in Ortakoy is nice, as is Reina.
Princess Islands: Really pretty, no cars, hour away by ferry.
Turkish Bath: Cemberlitas is the oldest and most lush
Afternoon strolls: Visit Cihangir and have coffee in one of the cafes. Narrow roads and antique shops, independent designers, boutiques etc.
Galata tower: Do it.
Basilica Cistern: Do it.
Hagia Sofia: Do it.
Blue Mosque: Blah. Essentially a big mosque that isn't actually blue.
Grand Bazaar: Would be lovely if it were void of over pushy salesmen shouting at you in German/Dutch/Japanese
Topkapi Palace: Nice to stroll in the gardens but not worth paying to get in to see the armory or harem unless you are into that sort of thing. A bit blah inside. Beautiful on the outside.