The usual tour is Fatehpur Sikri- Agra Taj Mahal, if you are coming from Delhi- Taj express (7 to 10 am)and returning (7pm- 10 pm) is ideal, you should pre-book your cab.
Insist on visiting the Taj first, as the temp increases with the hours. It would take 2 hours, then have lunch and head towards Fatehpur Sikri (35kms). Which is built with red stones.
The guides do not have proper knowledge and tell only myths. The vendors around will harass you to buy trinklets. you have to be very stern and bargain a lot (if they tell you 600, start from 50).
Do not go in the summer as you will be like a cat on a hot tin roof. The roads are pathetic, government has done nothing as far as preservation is concerned.