We recommend 'vapur's. Probably the most economical way of getting all accross the Bosphorus in a few hours. Never drink tab water in Istanbul. Standard 2-pin plugs are used all around the country with the exception perhaps expensive, luxury hotels. Voltage is 220 with 50 hertz.
Traffic is hectic and heavy in Istanbul almost all the time.
If you're into drugs, be careful at this moment. It's said the best stuff is out there, but you're not in Amsterdam.