By now books for most subjects would've arrived in the market. Check syllabus of every subject that interests you and then check its books. Get a feeling for the subjects and then choose keeping your interest as top priority. Start reading DAWN daily from tomorrow onwards (Opinion, Editorial and International pages mainly). Improve writing as much as you can and as one person above said, 2-3 weeks in an academy will get you well-oriented in my opinion. Rest you have to follow the syllabus and do smart study. Although I am not saying that Jehangir's books are of a great quality, but I think we have a short time and they would be helpful (JWT World Times magazine is good too). The internet is also a very useful resource.