Check out these websites:
http://www.eiaonline.com/intercepts/2010/05/17/the-top-20-education-blogs/
http://www.edweek.org/ew/section/blogs/index.html
http://www.educause.edu/EDUCAUSE+Review/EDUCAUSEReviewMagazineVolume39/EducationalBlogging/157920

and  there are many more:  just type in education blogs in the search engine.