This week Technorati, the blog search engine, is releasing its annual state of the blogosphere report, with new chunks of information every day for five days.

If you’re into numbers or want to compare your blog to the blogging world at large it’s fascinating stuff – and probably fodder for lots of posts for your own blog. Day 1 was the intro, Day 2 covered the what and where of blogging, Day 3 (today) is the how; Day 4 will cover blogging for profit and Day 5 is “Brands Enter the Blogosphere.”

Here’s a link to the introduction. From there you’ll see links to the other sections that have already run.

Some interesting facts:

Blogger tend to be well educated and well off.

Three out of four U.S. bloggers are college graduates, and 42% have attended graduate school. They skew male, and more than half have a household income over $75,000. They are experienced: although it has only recently exploded into the mainstream, blogging is not a new phenomenon. Half of bloggers are on their second blog, and 59% have been blogging for more than two years.

Plenty of blogs, but only a fraction get linked to. Technorati tracked 5 million blogs that had at least one new post in June 2008; of those, 75,000 blogs had a Technorati rank of 50 or more, meaning at least 50 other bloggers found the content valuable enough to link to. (With a Technorati ranking of 54, WordCount just squeaked by that milestone.)

Blogging is good for your career.

The majority of corporate and professional bloggers have seen a positive impact as a result of their blog. Half are better known in their industry, and one in four have used their blog as a resume enhancement. Fewer than one in ten have seen a negative impact from blogging and one in three have yet to see an impact.

Blogging takes time.

One in four bloggers spends 10 hours or more blogging each week, and about half spend more than five hours weekly on their blog. Only 15% of active bloggers spend less than one hour per week on their blog.