Avoid printing by mistake

Select Tools | Options from the menu and click the Security tab. Check the box that says Warn before printing... and click OK. If you were using Word 2007, you'd reach that check box in a
different way. Click the Office button at top left, click the Word Options button, click Trust Center in the list at left, click the Trust Center Settings button, and click Privacy Options.

Yet another option is to format each private document so that its text simply won't print. Highlight the entire document by pressing Ctrl-A, then right-click the text and choose Font. Check the Hidden box and click OK. Now select Tools | Options, click the View tab, and check the box to show Hidden text. (Word 2007 users will click the Office button, click Word Options, click Display in the list at left, and check the box to show Hidden text). You'll see the text, but if you accidentally print it, a blank sheet will come out.