There are a few plans that have CAD drawings that users have provided. The few cad files that are available (".dwg" and ".dxf" files) can be viewed and printed with a most cad programs. A FREE viewing only program is available at sourceforge.net . If you need to view them and dont have a renderer then you can get the latest version you find there. Its no longer being updated but used to work pretty good.

The ".png", ".jpg", and ".gif" files are best viewed and printed from your favorite photo editor. After you have followed the image link to the point it is no longer a link and is taking up the entire web page, Save "The Image File" on your local machine by right clicking on the big image you want to print and select "save image as".