This YouTube playlist,Searching Patents using Classification, was created to assist you in learning how to search patents. Most are less than 2 minutes. For further assistance contact Marian Armour-Gemmen.
"Guide to Patent Searching" http://www.lib.utexas.edu/engin/patent-tutorial/index.html
The best webbased tutorial is from the University of Texas. This guide gives you the steps while you navigate the PTO website
"How to Conduct a Preliminary U.S. Patent Search: A Step by Step Strategy"
A 36 minute Video from the USPTO
Patent Searching at Auburn University