The best way to start the visit to Agra is to arrive to the city in the evening by train from New Delhi, so you can get to Taj Mahal early in the morning before it gets super-crowded. We stayed in a cozy hostel named "Zostel", where we also had dinner and breakfast.
You have probably seen the pictures of Taj Mahal thousand times, but still, when you enter the arch and you see the mausoleum in its full splendor, it is breathtaking. A lot of local "guides" will offer their services to you, but they would not tell you much more than you can read in a guidebook. If you still decide to take a guide - bargain hard for the price.
Catch a taxi or a tuk-tuk to the Red Fort. It is a magnificent complex of palaces and galleries. Plan at least two hours for the visit in order not to be in a rush. Exquisite marble carvings and beautiful regular gardens are worth exploring in detail.
This weird place is an hour away from Agra by taxi and it is much less crowded than the city. The palace and surrounding buildings were constructed by Mughal Emperor Akbar and served as the capital of the Mughal Empire for just 14 years. Then the Mughal died, another dynasty came to power and the palace was abandoned and remain so until our times. There are several impressive buildings, including the imperial palace and the mosque.