How can I print a Quick Guide to function keys for the POS station?

From POS or Manager press F1 Help. Under the Contents tab locate 'Moving around in POS', 'Function keys summary'.

Click on the Print icon in top menu bar. Accept the default 'Print the selected topic'.
This will print a 2 page summary outlining all function keys in POS. Custom macros are not included. 
A more detailed explanation of each function is provided in the topic section called Keyboard Guide. 

TIP: Use the Help/Print function to print quick guides to frequently used operations (how-to guides).