1) On the top menu, click on File > Page Setup

2) Set all Margins as shown and Orientation to "Landscape"

3) You may want to include the background images to properly print the site.
NOTE: Doing so will use more color ink from your printer.

a) On the top menu, click on Tools > Internet Options

b) Click on the Advanced tab, then scroll down until see see the section labeled Printing.  Check the box next to "Print background colors and images", then click on OK.

That should be all that's needed to produce accurate printouts for pages that are not specificed as printer-friendly!