There are many legal blogs, and one of the better comes from David Allen Green and his Jack of Kent blog - which can read at http://jackofkent.com. 

In his article in the Solicitors Journal he outlines three very good reasons why lawyers should blog, and one reason why they shouldn't. 

He suggests that blogging is a good way for a lawyer to develop as a lawyer, that it will help you connect to clients and peers, and that it fosters greater understanding of the law. 

He rightly abhors the bland blogs - those that I guess come from the suggestion of the marketing team.

I would add two further points.  Lawyers are not always great at expressing strong opinions.  If you have nothing to say, say nothing. 

And if you must blog, think about who you are writing for? A blog aimed, for example, at a specific group of clients is going to be very different to a one aimed at your peers.