I'd argue if you need to be told about keyboard shortcuts, then you're not a power user. (I.e., knowing how to find keyboard shortcuts I'd consider a core trait of power users).
For completion, system shortcuts are also available in `System Settings > Keyboard > Keyboard Shortcuts...` (where they can also be changed). (Although I don't think that's 100% comprehensive, e.g., I don't think `⌘⇥` for the application switcher is listed there.)