Sometimes the simplest advice is the best advice.
Leona and I spend a lot of time doing some really high-level SEO stuff like server configurations, targeted linkbuilding and universal search optimization.
But its good to get back to the basics every once in awhile!
Believe it or not Google actually has a few resources scattered about their web properties that do a great job of explaining SEO, for beginners and advanced marketers alike.
Here they are: