IELTS is the first choice international English language test for global opportunity
The definitive IELTS site. Up-to-date information about IELTS.
The site includes the latest Handbook, Information for Candidates and Speciman Materials. Also included are the band scores and descriptors for the writing and speaking tasks. Although it's a 'must' for teachers and candidates, it's a first stop kind of site. It has some usful samples and test day advice, but doesn't have teaching resources or section tips for candidates - these are on the Cambridge site http://www.cambridgeesol.org/teach/ielts/ (see above).