Edublogs has been set up to allow teachers and pupils to create and manage their own blogs, and in itself offers potential in many subjects (see http://edublogs.org), even just as a source of links and resources.Larry Ferlazzo has an Edublog that was originally written for English language learners in the USA, but has grown to now cover other subjects via his Best of series, and Websites of the Year and Month. Alternatively, a search by category reveals links for Geography, Grammar, Health, Educational games, Music & Art, Reading, Technology, Science and Writing, plus many other resource links.
Take your time to explore http://larryferlazzo.edublogs.org carefully, and http://larryferlazzo.com/index.html for more links about English, Maths and Social Studies (History & Geography).