You can D/L the .pdf of the NCAA Rule book from here,
NCAA Publications - 2009-10 NCAA Football Rules and Interpretations (2 Year Publication)
The officials in the UK have it online (
British American Football Association ) and they have the approved rulings shuffled in after each Rule which is very convenient.
They are 99.9% identical to the NCAA rules with a few minor changes to allow for UK specific things, e.g. 90yd fields. Simply click on the Rule number link for direct online access or click on the PDF tag to open a pdf.