There are numerous Mathematics blogs out there!
Use Mathblogging.org to see recent posts from an extensive collection of blogs.
The Edublogs Directory has a Math and Science Section, like Mathsblogging.org it is possible to see when each blog was last updated.
Craig Barton has included some of his own favourite blogs in this video (thank you for the mention Craig!):
A blog I have mentioned previously is ‘Teaching AQA GCSE Maths’ from the Longman Maths publishing team. Obviously this is of particular interest to teachers teaching the AQA specification, however they sometime provide free resources of interest to any Maths teacher. This post for example features a free algebra resource including teachers’ notes. This works very well on the interactive whiteboard. An earlier post gave a link to a free book – ‘Street Fighting Mathematics’ by Sanjoy Mahajan. The post includes a link for a free pdf download. This page of their blog has links to many free resources. Thank you Longman Maths!
Some more of my own favourites include Dan Meyer’s blog, Don Steward’s Median, and Guillermo Bautista’s very well organised ‘Mathematics and Multimedia‘; this includes an extensive collection of clear tutorials on GeoGebra. From fellow Maths TES Panel members we have Dave Gale’s Reflective Maths, Paul Collins’ Mathematics Blog. Sharon Derbyshire and Laura Rees-Hughes Number Loving , Damian Watson’s Teaching Maths and Great Maths Teaching Ideas from William Emeny.
On the subject of blogging itself see Blogineering from Guillermo Bautista and Riley Ayes. The very busy Guillermo discusses the connection between mathematics and other fields such as the arts, music, poetry, and other sciences under the Math Palette category. A favourite post of mine has to be on The Mathematics of Hairdressing!
The blog you are reading now is a WordPress blog – see my very first post for some useful links on learning to use WordPress. See also this link for some useful information on using Blogs with students.