What is the L visa process for US Permanent Resident, yet citizen of another country?

Hello,
Thank you for your time. I'm a permanent resident of the United States (I have my permanent resident card) and I am a citizen of The Democratic Republic of the Congo (I have a current passport). I will go to the Chinese consulate in Los Angeles. I look to visit China this coming December for 2 weeks (in Shanghai). Is there a process that I need to be aware of?

Also, did I read the information clearly, I have to buy my airline ticket first (it will be non-refundable to get the best price) and then apply? What if it is rejected for whatever reason? I do have my hotel confirmation (Marriott Hotel in Shanghai).

Thank you,

Said