Learn the basics about Worker (in other words: What you should know when using Worker).
Read about features which are nice to know when using Worker.
Here you can find information about advanced features which usually increase the productivity.
If you want to start adding new functions in Worker using buttons/hotkeys or file types you should read the workflow information. You can find details about the execution of commands and what is used and what not.
If you want to translate Worker into a different language, read the translation page for details.