there should be 2 acceptable links to help you figure out how to make a shield similar to the shield that is shown in my previous two posts.  I could not find the blog that i used to help design my shield.
(I do not advise using 2 by 4's)

http://www.hurstwic.org/history/articles/manufacturing/text/viking_shields.html
http://www.vinlandvikings.org/Shieldconstruction.html