If you have not taken IELTS before, make sure you take it soon, so that you know what your current IELTS score is. It's good to know that, when students take IELTS for the first time, many get a lower score than they expect. This is normal because they are getting used to the test; they are starting to understand what they need to do in the test. The second time they take the test their score usually goes up. The key question is: What is the gap between your current score and the required score? Knowing this will help you plan and make decisions about your self-study preparation.
These links provide basic information, advice, and practices to do with IELTS self-study.