Salam Brother,i think you have ample of time to begin with.I had only 75 days with subjects like Applied mathematics and physics. So I can suggest you the procedure I adopted for my self.
1. I had no idea of the books selection,but I had internet Facility available.So I decided to Pick a topic from syllabus and Google it.
2. Initially I studied 2-3 subjects a day,but after 3 days i realized none of the subjects could be focused.
3. I initiated from the subject that matched my engineering background so that I should build study tempo.It took 6-7 days to cover entire physics( except few topics)
4. I found
www.wikipedia.com extremely helpful for General science and current affairs because often the papers are not exactly according to syllabus( or some aspect).wikipedia gives you related topics which are very very very helpful. Current affairs paper( from which I was fearing the most) was 65% paper according to the suggestions of the wikipedia.
5. Take notes of each important point on plain paper(with diagrams if applicable).
6.i found websites for improving English in making summary and Composition.More over wikipedia uses quality English.the standard of the subject can be made better by just browsing different topics on wikipedia.
7. Do not manage time for study from your daily routine , rather manage time for these things out of your study.
8. Important is quality of study,Not the quantity.
9. dont forget to use
www.youtube.com for video lectures and demos.
For any other question,feel free to ask brother.
Regards