The Economist's author style guide is full of great writing advice (though the writing style, ironically, might put you off). I particularly enjoyed this passage:
"Do not be too didactic. If too many sentences begin Compare, Consider, Expect,Imagine, Look at, Note, Prepare for, Remember or Take, readers will think they are reading a textbook (or, indeed, a style book). This may not be the way to persuade them to renew their subscriptions."
Essentially: keep your sentences short, avoid clichés and jargon, and favour clarity.
If it's good enough for the Economist, chances are, it's good enough for your blog.
Keep in mind George Orwell's six elementary rules ("Politics and the English Language", 1946): Never use a Metaphor, simile or other figure of speech which you are used to seeing in print. Never use a long word where a short one will do (see Short words). If it is possible to cut out a word, always cut it out (see Unnecessary words). Never use the Passive where you can use the active. Never use a foreign phrase, a scientific word or a Jargon word if you can think of an everyday English equivalent. Break any of these rules sooner than say anything outright barbarous (see Iconoclasm). Do not be stuffy.