Punctuation Marks Ranked From Worst To Best http://www.buzzfeed.com/emmyf/a-definitive-ranking-of-punctuation-marks#lgokmb Commas can be kind of assholes because they confuse the living crap out of everyone on earth — with the word “which,” with quotation marks (inside or outside?), with nonessential vs. essential clauses, and virtually any other situation that can and will arise in a sentence. When used properly, however, they lend plenty in the way of emphasis, emotion, and clarity.
Web Typography, A Long Dark - This is an interesting slideshare on how typography works in today's internet. It is vital that you understand how this works in order to design pages that work! (And are readable).