This is one of my favorite articles on typography. A few of my highlights:
1. Use one space after the period.
2. Indent to start a new paragraph (no need to have a blank line and indent).
3. Use smart quotes!
Some of these principles are only applicable to print typography. Also, please don't use fancy dashes or quotation marks as this can cause all kinds of i18n issues when the text is copied or transformed.
How pedantic. Two hyphens is a dash, and the "'" character is perfectly usable everywhere you want a single quote or an apostrophe.<p>Does it really matter how many spaces after a dot one uses, or if dash is really a dash or just two hyphens[1], or how paragraphs are handled? No! <i>Nobody will even notice!</i><p>Work on actually getting things done, not adhering to the standard this rag of a publication mindlessly pushes.<p>[1] As it has been done since the dawn of computing.