Making my html5 page backward/cross-browser compatible

Project Description:
This is a very simple project for anyone who knows what they are doing and should not take more than hour at most.

The front page of my site www.bookdb.co.uk is using html5 mark-up, I am trying to use modernizr (www.modernizr.com) to make the site backward compatible with older browsers such as IE7 & IE8 that do not support html5 browsers but it does not seem to be working.

All I need is someone with the experience to implement the right script (if necessary) to make the site backward/cross-browser compatible.
It must support all the most commonly used browsers along with the different browser versions.

Please do not bid ridiculous amounts of money for this project as I am aware of the kind of prices pages cost to design.

Additional Project Description:
02/07/2013 at 22:57 EET
Note: I only you to change the index page (1 page)