www.oup.com/elt/result. You'll find quite a few resources, but especially have a look at Words and Phrases - Key vocabulary.
The vocabulary is presented clearly unit by unit, and was new to me as well (see, I don't spend all my time surfing the internet :-) )
Now for the essays:
Say what you are going to say.
Say it.
Say what you've said.
Say what you've said.
The layout is simple. You have an introductory paragraph where you will have your key statement. This tells the reader what you are writing about and what your position is.
The body is divided into 2-3 paragraphs, each of which should have a topic sentence, which tell the reader what the paragraph is about.
The concluding paragraph sums up.
This is a powerful tool for writing an essay successfully, and even more useful if you also use it when reading.
Remember when I told you to 'look at' the text before you begin reading it?
Basically, all you need to do is find these key sentences and you will already have an idea of the topic and the writer's view.
If you want more on the subject of essays, especially is you decide to take the IELTS, then this link may help you: Basic Guide to Essay Writing