There are many places on the web where teachers can go to look for resources to prepare their classes or to learn methodology.
ESL-lounge offer free lesson materials for ESL classes. Fully printable worksheets: song lyrics, reading comprehension, board games, ESL articles, guides to English grammar, pronunciation materials, all classified according to level, from beginner to proficiency.
Isabel’s ESL site contains exercises, web based materials, workshops and webquests, all created by an English teacher, plus a collection of links to other ESL sites.
The Internet TESL Journal is a monthly web journal with articles, Research Papers, Lessons Plans, Classroom Handouts, Teaching Ideas & Links.
Dave’s ESL café Plenty of stuff for teachers, such as ideas for your teaching in Idea cookbook, and for students: idioms, phrasal verbs, quizzes and slang.
APAC Associació de Professors d’Anglès de Catalunya. In their website they offer multiple resources for teachers and learners of English alike, and news on the association and the annual ELT convention.
CRLE Centre de Recursos de Llengües Estrangeres. Information on the Orator projects and Pla experimental de llengües estrangeres, guidelines and support materials for the teaching and learning of foreign languages, plus a good collection of useful links.
For those of you working in CLIL (Content and Language Integrated Learning, that is, teaching another subject in English), you will find a number of materials at
http://phobos.xtec.cat/cirel/cirel/ Enllaços Catàlegs Delicious per a la implementatció de l’AICLE (CLIL) and also Materials
Apac in Classroom resources - CLIL
Many American sites offer lesson plans and activities for the different areas of the curriculum. One of such, with excellent materials, is Discovery School, under Lesson plan library or Fun tools: Curriculum center, Worksheets to go, Learning Adventures.They are not intended for ESl learners, so they may require a litle bit more adaptation.