The National College for Computing Education, NCCE, have produced a comprehensive curriculum for teaching computing in Primary and Secondary schools. Follow this link to the site. Combine this with an e-safety curriculum from Education in a Connected World and your students will have an excellent start. You can also find the e-safety curriculum online by going to Project Evolve.
Of course there are many other resources that can supplement and extend the lesson plans and objectives from the NCCE scheme of work. In this document we reference other complementary resources.