Teaching English is a co-production between the BBC (British Broadcast Company) and the British Council.What called my attention is the fact that both organizations receive funding from the UK government for their work,so all the material in this site is totally free.We can access the content in three main ways: as a forum, where people can discuss different teaching aspects, as a webresource containing good and free EFL material and as an theoretical arquive, containing articles about teaching ideas and techniques.This site is amazing!!!
There are many free activities, lessons for teaching English in primary school and in each lesson they suggest some sites and teachers reference.If you want to receive free lessons plans and newsletters, you can register your e-mail there.
Check you vocabulary knowledge or improve it more!!
These are my suggestion, then I'll post more links about ESL sites.