I don't think that I have much beginner-friendly content on my site, alas I think that MerricB's two articles on Canonfire! are definitely among the best intros to Greyhawk out there, along with (at the conceptual level), Nitescreed's old "Grey in the Hawk" essay and GVD's style guide follow up (also in the Paizo post). Despite some of Nitescreed's essay's flaws, it's full of good inspirational ideas, much like Montand's "Future of Greyhawk" post from Greytalk ~10 years ago.
Greyhawk is what you make of it, so throw some ingredients together that'll taste good to you and your players, then throw some dice!