The International English Language Testing System (IELTS) determines the English language skills of candidates who need to enrol in higher education or work in a place where English is the main language of communication.
IELTS resources
IELTS.org: The official IELTS exam website with lots of relevant information on exam format, how to register, where to find an IELTS test centre, sample IELTS questions, sample candidate responses with examiners’ comments, and tips on preparing for the exam.
IELTS Ready Premium: An online preparation course by IELTS experts. It has interactive activities and videos that give advice on preparing for the test.
Takeielts.org: This British Council website is full of useful tips.