Tourist visa for a Sri Lanka person

Hi,
I am going to visit China in coming April for the first time.I have no relative their.I am going to reserve a hotel by myself without contacting travel agent.I already made my travel plan.
How can i apply for tourist L.Do i need to submit any invitation letter from Chinese embassy or any travel agent to apply for tourist L.
Or else submitting air ticket copy,hotel reservation confirmation letter and passport copy together with the application enough.Please advice me.
My email address is oshadeeleapbis.info
Look forward to hearing from you soon
Thank you