The old Standards Units produced a great set of resources including lesson activities and a booklet supporting teachers in using these and other rich tasks. They seem now to be managed or have changed into the QIA and the resources were called "Improving Learning in Mathematics." They can be downloaded or viewed on line at:
http://teachingandlearning.qia.org.uk/teachingandlearning/downloads/default.aspx#math_learning
The general booklet supporting teachers in using these resources or in taking some more risks to develop mathematical understanding can be downloaded via this link to the NCETM website: http://www.ncetm.org.uk/Default.aspx?page=13&module=res&mode=100&resid=1442