More than books, you should indulge in auditory and reading skills. The tricky part of IELTS, in my opinion, is the Reading Module. The speed with which you read and understand the content within a limited time is very crucial. Your brain should get accustomed to understanding a given sentence by reading in the first instance itself. Make sure you pay your 100% attention to each word and understand the essence of the paragraphs. For example, a question such as; "What does the author infer in the given passage?" - does not have an answer that you can necessarily find in any particular para, hence understanding the message behind the text is your best bet to answer the comprehension. So, concentrate more on reading day-to-day articles in newspapers or online for the Reading Module. The other three modules: Listening, Writing and Speaking; are rather simple. For a person who speaks on an everyday basis, Listening and Speaking should not be a problem whatsoever. In conclusion, I suggest you not to worry too much about the number of books you read for the exam, rather, spend your time on improving your quality of the language. Improve your vocabulary - a good book to help you build your vocab is Word Power Made Easy by Norman Lewis. It's a holy grail for almost all of the GRE, IELTS/TOEFL aspirants. Make it a point to have frequent conversations in English with people around you. Last but definitely not the least, take one or two online mock tests before you give your final. This is always an important step to face any examination. All the best! read less