If you have only two days in Beijing, this two-day tours probably will be the best solutions for you. 

Day 1: The Tian'anmen Square , the Forbidden City,  Jingshan Park, the Old   Beijing Hutongs, Acrobatic Show.

Day 2: The Great Wall , Ming Tombs and the Olympic Venue, Kongfu Show.

PS:

The above price is the package price for all the entrance tickets for two days for one person,  but not include the sevice fee of the guide 400yuan/ Day for a person or a group and the transportation fee which we could try to use subway, bus or to hire a private van.