Well, I remembered from other teachers having this need to print a grid - that there is one thing you need to know.
On Microsoft Office -
Go to File - Page Setup - and then check what you do want to print.
On Open Office - the setup is slightly different. You go to Format - Page - Sheet and then check what you want to have printed.
This is a very simple tip, but one that I get asked often. If there is nothing on the page, you need to put a period at the very end cell to get the gridlines to print for the whole page.