Hi, I have just finished my post on this. http://ambhad.com/2008/05/02/wordpress-seo-secrets-exposed/ Tell me is it all correct?
There are some glaring errors in there, specifically the use of heading tags. While I like the idea of consistency between URLs, I find it's much easier to use mod_rewrite to force them all to use a directory-style structure for starters. WordPress does default to the www. version though it does not correct for the index.php issue - mod_rewrite is your best bet to fix that (without having to use the Enforce www. Preference plugin). With regard to the TITLE and META tags, the All In One SEO Pack will handle all of those jobs, thereby cutting down on the number of plugins needed, which will also use fewer server resources. It also doesn't go into enough detail on duplicate content issues either or how to resolve/prevent them. You might want to check out my "WordPress SEO Checklist" post in my signature link here on the forums for more information.