Yes, you can take shuttles outside of the airport, just ask the Beijing airaport staffs. Shuttles from the Beijing airport only cost you 16 RMB, very cheap for anyone. The routine is :
1. Sanyuanqiao;
2. Dongzhimen;
3. Dongsishitiao Bridge;
4. Xidan (Civil Aviation Building).

Just remember their time is 6:00am-7:30pm.

Or you can take taxi which cost a little much, it depends on different taxi companies, around 60-120RMB