Blogs are not traditional media, and bloggers are not journalists. Unless they are. But it's not a requirement. A blog is software. It's something one puts up on the Web to capture and disseminate information, of whatever type one wishes, and thus, if anyone tells you that you're doing it wrong, that's just silly. There aren't very many wrong ways to do it (except for illegal things, like stealing from others). And yet . . .
If you're going to blog seriously, keep in mind the following:
Consider the goals and value of your posts. Are you adding to a body of work? Are you blogging to educate, to inform, to deliver some value?
Facts do matter. If you're stating opinions, stress that they're opinions. If you're claiming a fact, try to cite sources. (I tend to state mostly opinions.)
Remember that defamation is still a potentially legal issue.
You can always ask questions before you blog (a novel idea, I know).
Brevity matters. I know that I blog about this often. I see a number of posts where one has to wade through to try to decipher the salient points (often my own).
Disclosure is key. If you're doing something to make money, if you have a business relationship with an organization that you're writing about, if there's anything that might potentially change the way something is perceived were it be to be measured against what you wrote, it's better to disclose that.
Link when you're mentioning other sites or information that have links. It's good ...