visa type L documents required

Dear,
I'm Italian and i will travel to Thai on November. I would like to know in few simple steps how can i get the chinese type L (tourist) in Thailand.
In China i am invited by a friend and my accomodation will be his home.
Which documents/photos are required? Should I go to do it in PRC embassy or are there any agency that can do all the stuff for me?
How long will it take?
Ale
Thanks in advance