To print any document in KeepandShare, first view the document by either clicking on the document title or, if you're currently editing the document, click on the "View or Print" button on the left side of the editor:

Once you are viewing the document, then click on the Print button in the center of the row of buttons at the top of the viewed document:

This Print button immediately opens a new browser window with your document formatted for printing in it, and with the browser's print command already issued such that the print dialog is opened. Now make sure the correct printer is selected, and click on the Ok button and your document will be printed.