Hi siddiquis, you can't learn much by conversing just over skype. Get some instructional materials such as CD tapes and books from British Council or other Book shop outlets and do a serious study. Remember, you will be tested in four areas. So, conversing over skype might help to improve your speaking and listening skills but that is not enough. You need to learn core IELTS quetions and how to answer them. Good luck in your exams.