In my mind, Varansi is the saffron city. The colour of the ancient reliogion of Hinduism, the colour of the marigold flowers that are used for worship and the colour of the clothes that are worn by the sadhus and sanyasis who flock to this holy place.
I have been to Varanasi multiple times....for tourism, for work and for a friend's engagement ceremony. From Kolkata there are numerous trains that go to Varanasi of which Rajdhani Express is the fastest. Flights are also available daily.
For a tourist, the best place to stay in the city is at Assi Ghat.There are numerous hotels of various budgets here, though the 5 stars are in a different part of town altogether. The variety of food on offer at Assi ghat sets it apart from the rest of town which is predominantly vegetarian. Yes, you will get non-veg here! :)
The city stretches from Varuna Ghat to Assi Ghat (the 80th ghat) hence the name Varanasi. The main attraction of the city is the river Ganges and the ghats. The rest exemplifies a typical U.P. town, albeit with history.