These are keystrokes that are synonymous with nearly every application and program available on the PC market. These are important to learn because often one is not given the option within a particular program or screen to complete one of these commands from a pull-down menu. Also, these may help dramatically save work time and ease work tasks.

Cut, Copy, Paste and Undo keystrokes
(4 of the most important and useful keystrokes!):
Ctrl + z = Undo your most recent action
Ctrl + x = Cut
Ctrl + c = Copy
Ctrl + v = Paste

Moving within a document:
Ctrl + End = Go to end of document
Ctrl + Home = Go to beginning of document
Ctrl + Down/up arrow = Go to next/previous paragraph
Ctrl + Right/left Arrow = Go to next/previous word

Highlighting Items: 
(to re-format or delete a letter, word, row, paragraph, or entire document)
Shift + Down/up arrow = Select a row of text
Shift + End = Selects from cursor to the end of a line
Shift + Home = Selects from cursor to beginning of a line
Shift + Right Arrow = Select a letter, or many letters
Ctrl + Shift + Right/left Arrow = Selects one word at a time

* Please test each of these keystrokes in every-day scenarios.