Turns out that the advice that librarians have been spouting for years about evaluating Web sites goes for blogs as well–
When it comes to blogs, no one can screen them for you so keep this advice in mind - if you cannot ascertain the identity of the blogger, don’t trust what you read without corroboration from a trusted source. Common sense goes a long way whether you’re reading a blog, newsletter, newspaper, prospectus, etc.
— Wise words from Neil Squillante over at TechnoLawyer Blog
Another aspect of blog evaluation may lie in determining the influence of a blog – who is citing it. That’s where a little tool called BlogPulse comes in handy. I’ve mentioned it before, but it’s worth repeating. Its blog profiles will show you how active the blog is and how it ranks compared to other blogs. Nifty.