Some useful information for tourists:

The city water is not drinkable:

The tab water in Istanbul is not drinkable. You can buy any kind of water (mineral, natural etc.) from markets or kiosks that you can find in every corners of the city. Those waters are usually sold in plastic bottles.

Money:

In Turkey you should get used to zeros in Turkish Lira.
There are currently 3 kind of coins:
50.000 TL.
100.000 TL.
250.000 TL.
And 6 kind of banknotes:
250.000 TL.
500.000 TL.
1.000.000 TL.
5.000.000 TL.
10.000.000 TL.
20.000.000 TL.

Transportation: (The prices given below are in USD currency)

Istanbul as a metropolitan and has many alternatif ways to travel in:

Public Bus
In the city, there are two different busses. One is the public busses (I.E.T.T. busses) and the other is the orange busses (Halk Otobusu). To get on the public busses, you have to buy ticket (coast about 45 cents) from ticket windows in the bus stations before taking the bus. In the orange busses (Halk Otobusu) you have to pay the ticket price in cash to the ticket seller in the bus. The ticket prices are same in both busses.

Tram
There are 2 kinds of tram. The modern one is running throughout the historical Peninsula and some suburbs of the city. Tokens which you can buy in ticket windows in the stations are used and coasts about 45 cents. The other nostalgic one runs throughout Istiklal Street which is famous for its old buildings and night life in Beyoglu. The ticket of public bus could also be used for this tram.

Metro (subway)
Metro has started to run in one line only. The construction of other lines are still going on. The line is running between Taksim Square and Levent. Token for metro coasts about 50 cents.

Boat
Boats are the significant aspect of Istanbul. Boats are running to many points from the ports such as Eminonu, Karakoy, Besiktas, Kadikoy, Uskudar and so on. Before you take the boat you should get token which coasts about 50 cents.

Taxi (yellow cabs)
There are over 25.000 taxis in Istanbul which you will realize as soon as you arrive. Taxis have two kind of tariffs; day time (06:00-00:00) and night time (00:00-06:00).

Transport from the airport to the city center
On arrival at lstanbul Ataturk Airport there is a rapidly improving bus service (HAVAS) to take you through Aksaray, where you can take tram to reach our hotel, to Taksim Square and other central points of the city. Your second alternative is Airport taxi to reach the city center.

Telephone directory:

Istanbul has two telephone codes:
216 is the code for the telephones for Asian side and 212 for European side.
If you want to make a phone call between two sides, you should dial 0 212 from Asian part to European part and 0 216 from European part to the Asian part.
The dialing system and the number of digits for telephone numbers are in international standarts.

Some emergency phone numbers:

110 Fire
112 Emergency/Ambulance
154 Traffic
155 Police

Some useful words and phrases:

Hello: Merhaba
How are you?: Nasilsiniz?
Goodmorning: Gunaydin
Goodnight: Iyi geceler
How much?: Kac para?
Room: Oda
Key: Anahtar

Numbers:

1 Bir
2 Iki
3 U
c
4 Dort
5 Bes
6 Alti
7 Yedi
8 Sekiz
9 Dokuz
10 On
100 Yuz
1000 Bin
10000 On bin
100000 Yuz bin
1000000 Bir milyon
10000000 On milyon
1100110 Bir milyon yuz bin yuz on