Istanbul Visit Information

www.letsgoistanbul.comwww.turkeytravelplanner.com

Best area is Sultan Ahmet, where the Blue Mosque and many other historical structures are located.  Search for hotels in that area on www.booking.com

Turkey as you know is a city divided in 2 halves, European side and Asian side.
It depends on which side would you like to visit.
At European side, you have Ataturk airport around 30 mins away from city depending on the traffic.
Area near Blue mosques is full of tourists and hotels, you may find a good hotel easily through www.tripadvisor.com

Asian side doesn't have much to see.  90% of sites of interest are on the European side, and well over half of them are in Sultan Ahmet.

Sultanahmet is convenient because it is close to most historical places, Grand Bazaar, old city, etc
Taksim is another alternative with nice hotels, close to an area with more cosmopolite area, restaurants, shopping, etc
I agree that stay on European side, as there are rare things to see on Anatolian side, may be Baghdad Str, which is a nice area for shopping with high brands and cafe and restaurants
Nowadays, there is tulip festival in Istanbul, so if you go to some big famous parks of old palaces like Emirgan, which is on Bosphorus, in European side, you enjoy the colourful landscape of tulips
Enjoy your trip

Thanks for information
someone inform Taksim is mot safe area!!!!

It has a reputation for being not as safe as Sultanahmet.  Aside from low level crime, it also has a tendency to explode into political rallies and protests.  Anyway, it is more expensive and more modern than Sultanahmet, so why stay there?  I am assuming someone going to Istanbul is interested in the historical sites, including old bazaars, not so much in the modern shopping possibilities.

Stay in Sultanahmet, trust me.  I have been twice and stayed there.  Sure, go visit Taksim during the day, but it is better to stay in the historical part.  Lots of small hotels (called as pensions in Turkey) in that area.  Check booking.com.

Regardless of where you stay, be aware and vigilant.  Best to carry your wallet in a front pocket.

Thanks lot for complete information.
which is safe payment to do while paying hotel bill etc via credit card or cash?

both ok
better not to carry too much cash with you everywhere
if you do booking through booking.com or via similar web page, you don't need to pay hotel at the hotel, may be some extras only