Jinshanling’s Great Wall Section

Hello I am interested in the Jinshanling Section, we are going in december, Can someone advice about if it is correct to go to this section in this season or it is preferible go to another. Also Can someone help because I read in some website that you need to book in advance the tickets but I cannot find how to do it.

We are planning in one day trip to the wall and after come back to Beijing.

Thanks in advance for any help.
Regards