Eats, shoots and leaves: the zero tolerance approach to punctuation by Lynne Truss.

A nice little book that explains the rules and usage of punctuation, starting with the apostrophe and ending with a practical example of the importance a proper punctuation: the plagiarism of the British Government's dossier on weapons of mass destruction is obvious from the improper punctuation. Full of excellent humour, it does not shy away from telling about conflicts between different sets of rules.

Anyone interested in punctuation has a dual reason to feel aggrieved about smileys, because not only are they a paltry substitute for expressing oneself properly; they are also designed by people who evidently thought the punctuation marks on the standard keyboard cried out for an ornamental function.