Who can post:
All of you in the group are allowed to post a plan for a mapping event at any time you like.
What can you post:
Aside from mapping session plans, you are allowed to post about relevant topics such as news articles, cool images, information about other activities that are going on, etc (and yes, memes are allowed!).
The post must include the start time of the event (in British Standard Time to accommodate folks from around the world) pre-determined or determined by vote. As for content, I do recommend focusing on one or a few tasks from the HOT tasking manager per event. You should write the goal of the event in the post and include a link to the task. The link to HOT tasking manager is here.
The plan can take any form, depending on how large you intend your event to be. I recommend the following course of actions for the following situations: