I recently wrote an article on how to perform home page redirects which will help in SEO. A home page redirect is where www.mydomain.com/index.html is redirected to www.mydomain.com/. This gets the search engine bots to your home page in only one way: www.mydomain.com/. Of course you should also redirect mydomain.com to www.mydomain.com.
If you should change your home page to index.php it can easily be redirected to www.mydomain.com/ without loss of link juice. Note the redirect code works for all subdirectories, too. For example, if you have www.mydomain.com/products/index.php it will be redirected to www.mydomain.com/products/.
Note this article is for web sites on Apache servers since it requires modification to the .htaccess file.
Doug
Tags: home page redirect, www redirect