You can also follow GeoGebra on Twitter and Facebook.
From MEI, for KS3 have a look at these free GeoGebra interactive online classroom activities to support maths recovery at Key Stage 3. You can try the first three of five Algebra resources. Each lesson not only has a GeoGebra activity for use in the lesson, but also one for student independent learning. Full lesson plans and comprehensive notes for teachers are provided.
From Edexcel:
A Guide to using GeoGebra when teaching AS and A Level Mathematics.