Pancake provides a rich set of components in the recent releases and therefore it is not very practical to write manual for each one. We would like to recommend you:
Go over examples. Latest release of Pancake includes a diversity of examples. It's far better to get how each component work and how they work together.
Refer to Pancake page on Grasshopper Docs. They may not be up-to-date but provide you with a centralized view of Pancake components.
Description in each component. Besides that, Pancake now is smarter in the detection of any misuse. It will notify you if it thinks anything is wrong.
You can always drop us a message if you have a specified question not covered elsewhere! Refer to Contact.