This is required reading before you redesign/renovate your website. You could lose all of your cherished search engine rankings for a significant time or even permanently. Here are a couple sites I've found that half already covered the topic.
Oops, I Redesigned My Website! Best Practices for a Website...27 Jun 2008 ... How can I make sure that I don't lose my search engine rankings? ... you'll be in a good position to manage your site redesign with care. ... reports we've read say that Google will come back again if a page fails once. ...After a redesign be sure to run a link validator on your website to be sure ...www.yourseoplan.com/website-redesign-seo/