Page and text navigation are essential to be a fast, and hopefully productive, pc user. Let us start with some basics.
Webpage/file manager navigation
Alt-Left/Right Arrows to go back/forward in history
Backspace to go back
Alt-Space-C is a faster/lazier Alt-F4
Alt-Space-X to maximize window
Alt-Space-N to minimize window
Application specific shortcuts
Tab then Up/Down Arrows to toggle result selection.
Enter to follow the page.
In most browsers:
Ctrl-T to open new tab
Ctrl-W to close tab
Ctrl-Shift-T to reopen closed tab
Ctrl-Shift-R or Ctrl-F5 to refresh page and clear cache
Ctrl-Left/Right Arrows to move cursor one word at a time
Ctrl-Backspace/Delete to delete one word at a time
Combination of arrows in combination with the keys above them on your keyboard makes mouseless text selection a piece of cake.
PS. a more developer-focused productivity article will come