What books should I use to prepare for the HSK 3.0 exam?

I suggest HSK3 book. Also, for getting good grade, learn more than HSK standard words. I suggest trainchinese flashcards and listening to cartoon. For writing, write your book as much as you can. Write your workbook, it has good points in reading and writing, some of them are question in real HSK 3 test. For listening, listen to your textbook and try to repeat sentences. Moreover, there's some cartoon in youtube in Chinese language that has full subtitle for learning, you can use them for listening and learning new words. I did these and I have pass exam in good grade two years ago.