How do I take the bus from Guangzhou Baiyun Airport to Hongkong, Frequency & costs?.

There is no direct bus from Guangzhou Baiyun Airport to Hong Kong. You can take the airport shuttle bus line 5 to Haizhu Square, then walk to the Landmark Hotel to take cross-border coach there for Hong Kong. Or you can take subway line 3 to Guangzhou East Train Station, then take train there to HK.