Step 1: Before even starting preparation for IELTS, go through their official sites (either IDP or British Council) to understand the format of the test. It might seem trivial, but it helps to understand the format of the exam and how to plan for each section of each module.
Step 2: Give a couple of tests from the Cambridge test series to understand where you stand and which are your weak areas. At some point, you might realise that you are taking a little extra time on your reading section and need to tweak your reading habits to get a good score in the stipulated time.
Step 3: Listening section. For beginners, I would suggest starting listening to BBC News to help get a grasp of various accents (especially the British accent). For people who already have a good grasp of the accents (I have a decent grasp of different dialects), there are listening tests on YouTube you can practice whose level of difficulty is much higher than the actual IELTS test. I suggest giving such tests which will boost your confidence.
Step 4: Reading section. For these tests for the IELTS academic module, which equals 52 reading tests in total). By the 5th book, you'll be confident enough to get at least 7.5 to 8 in this section in case your reading skills are excellent. For others, it might take 13 books to achieve the desired score.
Step 5: Writing section. It is the section where most people struggle with. For beginners, I would suggest to first read some books on grammar. Reason being, proper grammar will provide you with a strong base to communicate your ideas to the examiner. Once you are confident about your grammar, I suggest you go through various websites that offer writing templates and tips along with the structure of these types of writing tasks. Initially, instead of just starting to practice by writing your essays, I suggest going through the various sample essays provided in these sites to get ideas and to understand the structure.
Step 6: Speaking section. IELTS Liz has a list of most asked questions in the interview. Start practising them by answering to yourself in the mirror. You can also pay to a trainer to help you with this module and even practice talking to a stranger. I don't think practising with a friend helps because you have a certain comfort level with your friends and hence it will be easier to answer their questions which might give you a false sense of confidence. Thus, the suggestion to talk to strangers or trainers.