1) Know the terminology: an edublog is an educationally related blogs and edublogosphere is the community of edubloggers. (see also Definition of a Blog)
2) Read efficiently. Learn what RSS is, get an aggregator (I love Google Reader), and start subscribing to and tracking a few blogs (see What, Why, & How to RSS and Subscribe)
3) Go to Alltop.com (a great list of all the top blogs in all areas) look at the education feeds but don't limit yourself to people in education.
4) Look for awards. Check out the annual Edublogs Awards to see who the readers decide are the best. (However the award is still new and gain credibility but it is a start) Every November nominations go up and voting starts and the winners are usually announced in mid December. Click here to see the current 2007 nominations and vote if you haven't yet.
*See also Top 100 Education Blogs and 100 Most Inspiring Innovative Educator Blogs and Podcasts
5) Look for blogrolls in the sidebar margins of blogs you like to read (I have shared my blogroll form google reader in the right margin under My Shared Stuff "My Personal Learning Network Blog Roll". A blogroll is simply a list of blogs that one reads and follows. It is common practice of bloggers to share what they read so others can read and to create that edublogosphere community.
My final advice is don't spend all your time just reading blogs or waiting to long to join in on the blogging. When I first started, I spent way too long on the sidelines just observing were I should have been participating. So start commenting on other people's blog posts and start writing your own right away.