Almost all operating monasteries of China gratuitously accept volunteers who want to get to know the life of the monastery, to study the philosophy of Buddhism, to depart from worldly vanity. For spiritual self-knowledge and development, I would recommend the "tested" temples: Longquan Monastery (Beijing, website) and Guanghua Temple (Putian, Fujian Province, website).

It will also be useful to get acquainted with the work of Bill Porter (Zen Baggage: A Pilgrimage to China by Bill Porter).