Here are some website suggestions to teachers and learners. They provide free helpful ESL/EFL resources.
Busyteacher - Printable worksheets and lesson plans for teachers on any topic with no registration for downloading materials
Islcollective - An international community of more than a million ESL/EFL language teachers sharing self-made language teaching materials
Sandy Millin - A site full of ideas for English teachers. It has some great blog posts on DELTA and CELTA.
An A-Z of ELT - Scott Thornbury's blog which covers all the key terms used in ELT and provides many practical ideas for ELT teachers
The Internet TESL Journal - Provides articles and links to almost everything in the world of ELT
ESL Conversation Questions - Hundreds of free conversation questions designed for the ESL/
Lesson Stream - Great ready to use lesson plans for teachers by Jamie Keddie
Englishwsheets - Worksheets that work great with kids
Dave's ESL Cafe - Besides its content, which covers almost everything related to ESL, it provides lots of job adverts for English teachers
ESL Logic - Presents online and printable logic puzzles organized by language topics
All ESL - Provides hundreds of good quality free printable worksheets which are created and tested by a team of teachers
English tools - Presents over 25 English language learning tools which range from tools that can turn your text into an image file or generate fill in the gap worksheets.
Englishpage - Provides free online English lessons with simple explanations
Englishclub - A huge website to help you learn English online
Ego4u - A general website to help you learn English
Apps 4 EFL - Provides many great online activities and digital tools for learners and teachers
Perfect English Grammar - A great reference point for English grammar
Agenda Web - A huge website of online exercises