The Core section provides information on navigating HS4, using the Setup and Tools sections, controlling Devices, creating Events, and using the Camera features.
If you need more assistance on using Devices within HS4, take a look at these docs.
For assistance on using Events in HS4, check out these docs.
Docs on using the Live View and Recordings within HS4.
Information on all of the various setup options and pages.
See here for using the various Tools provided in HS4.
See here for docs on HS4 plugins; installing, updating, registering, and more.