In the content author guide the most important things you will learn are:

How to install a H5P content type and create and edit H5P content

How to use many of the existing H5P content types

How import and export works

How multilingual content is handled

H5P provides an ever growing number of content types. Think of them as templates for creating content. To use a content type you only need access to a web site where H5P has been installed and a modern web browser.

You can also test drive H5P right here on h5p.org. 

H5P has been designed to let everyone create, share and reuse interactive content. Learn more about creating H5P content: