By extension - the best SEO guide is almost certainly the first listing for 'SEO guide' on google. Only if you can assume that they followed their own guide.

By extension - the best SEO guide is almost certainly the first listing for 'SEO guide' on google. Only if you can assume that they followed their own guide. I could see an SEO company posting a fake guide to make their own techniques more effective relative to any competition using that guide.