For foreigners the entry fee for the Taj Mahal site is 1100 rupees.
The opening and closing times are the following:
East and West Gate: Opening Time
Ticket Counter: 1 hour before sunrise
Entry Gate: 30 minutes before sunrise
East and West Gate: Closing Time
Ticket Counter: 45 minutes before sunset
Entry Gate: 30 minutes before sunset
The best light for photographing the front of the Taj Mahal inside the complex is in the late afternoon.
The best light for photographing the river side of the Taj Mahal is in the morning. There is a primitive boat that will give a small photo tour of the river side for around 150 to 200 rupees per person. It is outside of the East Gate of the Taj Mahal complex, down the small road toward the river at Map Location: 27.175809, 78.043826 .
There is also a viewpoint in a park across the river called Mehtab Bagh at Map Location: 27.178341, 78.040625 . The entry fee is 250 rupees. The views from there aren't as good as the views from the boat.