Blogging is a distinct genre, which shares the core conventions with and demands many of the strengths of other forms of writing, while asking authors to push themselves in novel ways.

The University of Sydney maintains a helpful website discussing writing online.  Its blogs help page has a number of useful resources.  Especially useful is its discussion of blog writing, which suggests in part:

• Write headlines that grab attention.
• Link to other sites. A lot.
• If you get an idea for a post from another blog, acknowledge that blog.
• Don’t plagiarise. Use blockquotes when relevant.

Style

• Identify your audience(s) and write in a style that is suitable for that audience
• Keep text brief and meaningful, readers tend to scan text
• Delete unnecessary words, limit your use of adverbs and adjectives
• Use short sentences and paragraphs
• Avoid repeating text
• Ensure consistency in style if you have multiple authors
• Put the most important message first
• Use the shorter word where ever possible, e.g. “now” not “currently”
• Avoid circumlocutions, e.g., “at a later time” for “later”
• Wherever possible, use the active voice, e.g., “Vet Science had a BBQ” instead of “The BBQ was held by Vet Science”.
• Check your syntax, punctuation and spelling

Layout

• ‘Chunk’ your content so that the page is not one large block of text.
• Use bullet point or lists
• Use sub-headings to put content in context

Links

• Use descriptive link labels, e.g., “Postgraduate timetable” not “Click here for Postgraduate Timetable”
• Link to further information wherever possible but be careful not to over-link, ensure links are relevant

With a less academic audience in mind, Philipp Lenssen offers a top ten list to guide bloggersng:

1. Use descriptive headlines that reveal the point of the article without further reading; the key here is to create microcontent that can fare well on its own. (An example of a good title is “Edit Captions in Picasa Web Albums” used at the unofficial Google System. An example of a bad title is the official Google blog’s “Greetings, Earthlings!”) Keep in mind the headline may be read in an RSS reader, a news portal which aggregates content, a search result, your blog archive, a bookmark and so on, and it may be surrounded by dozens of other headlines.
2. Write in inverted pyramid style: first get to the point and mention the core ideas, then fill in the details in later paragraphs. The first and second sentence should allow people to decide if they want to continue reading this.
3. The first link is the one most people click on, so it should also be the main link for your article. Also, too many links too close to each other diffuse your point and make you less of a filter, and a (news) blog should always be a filter for others.
4. In each longer post, re-introduce core ideas you mention because your readers come from all walks of life and may not be up-to-date (e.g. they may read your archived post half a decade from now coming from a search engine). It’s better to say “The Electronic Frontier Foundation yesterday announced … the EFF also said that …” than to say “The EFF announced… the EFF also said that …”.
5. Use lists, images, tables, sub-headlines, examples, indented notes, indented quotes, icons, colors, bold and italics to lighten up your article and make it easier to scan it. Don’t expect everyone to cling to every of your words; instead, you can expect a large part of your readers to sit at the office, a coffee in one hand and the mouse in the other, trying to get up to speed at 9 in the morning.
6. With a global audience it’s never a good idea to only use sophisticated words not everyone may know. Some of your readers may speak English only as second language. They may want to learn new words, but it shouldn’t come at the price of missing your post’s point. (If you only speak English as second language to begin with, following this rule might be much easier.)
7. Credit your sources with a mention and link. As opposed to mainstream news posts, bloggers usually tell where they got the story from.
8. Mark updates and changes (and do update and change when readers find something wrong in your writing).
9. Spellcheck your posts, and read them for clarity once or twice before posting. An error now and then isn’t bad but the less fewer errors, the more quickly people will be able to read and understand your article. (This rule, of course, is universal in writing and doesn’t just apply to blogging.)
10. To practically all of these rules there are exceptions. For example, when your post is very humorous in tone and has a punch line, you may specifically not want to give it away in the title. Or when you’re writing a longer essay, you’ll just have to live with the fact that you won’t be able to “cut to the chase” in the first paragraph. Another exception is that it’s not really necessary to mark every change, e.g. when you fix a typo somewhere in the text, or when you just posted 10 seconds ago. Not every post needs an image, etc. etc. And sometimes, breaking the rule is a conscious style element (e.g. this style of linking – not sure if it has a name – intentionally breaks rule #3).

In addition, another top ten list provides some useful tips. Other helpful notes on blogging include the always useful Idiot’s Guide and the Dummies Handbook.

I prize Racism Review and Newspaper Rock, reading them daily. They feature high quality posts, that to me exemplify the genre, reflecting critical thinking, engaged writing, and deep com/passion.  I will post comments on the rubric and assessment as well.