This is a work in progress which I will be adding to over the next few weeks. For now, see:
Number Loving is both a blog and resource bank run by 2 UK teachers, it hosts a large amount of lesson content and is a fantastic resource.
Matheminute is an amazing maths blog – absolutely packed full of interesting lesson ideas for extra-curricular maths.
Teaching Mathematics is a really thought provoking and well designed blog with a lot of lesson content ideas and also reflection on teaching practice.
Great Maths Teaching Ideas does what its name suggests, providing a massive number of teaching ideas – helpfully sorted into relevant areas of maths.
Math and Multimedia is another brilliant blog – which contains a huge amount of ideas and resources for using ICT in maths lessons. There are comprehensive Geogebra tutorials as well as information on using wikispace, Wolfram, and creating your own blogs. All this and a large, indexed collection of maths posts.
GFSMaths contains some great lesson ideas and a lot of visual content from lessons
Mr Barton Maths has a comprehensive list of both maths blogs and websites
dy/dan is a blog by Dan Meyers – in particular look at the 3 act maths section for some amazing ideas for creative maths lessons.
IB Maths Stuff – This is a great resource with free lesson notes on a large number of IB SL topics. It’s really well designed and well worth a look.