Entering China with L visa -- what documents do I need to bring?

I am a US Citizen and have a 10 year, multiple-entry tourist (L) type. When I arrive at the Beijing airport, what documents do I need to get through customs? Do I need records of a booked return flight (back to the US), a copy of hotel reservation, or any other documents? Or will I be let through with simply my passport/L type? Thank you