There are many Pronunciation books that come with CDs out in the market. They all promise to help improve your English Pronunciation.
Personally, unless you were born with ears capable of discerning the subtleties between æ, ə, ɑ, ʌ, to name a few, you will need a teacher, not only books. This is because there is a world of difference between learning something and putting it into practice efficiently as well as accumulating knowledge and obtaining skills.
English Pronunciation, like other skills such as speaking, cannot be acquired simply by reading Pronunciation books and listening to CDs. And even if you can discuss thoroughly how, say /ɑ/ vowel sound is produced, but you yourself cannot intuitively make the sound especially when you speak, you are as good as the textbook.
To put it simply, if you are not one of the few gifted people who can teach themselves sounds effectively , which is evident in their speaking, you need a reliable Pronunciation teacher, not a book or CD, to help you improve your English Pronunciation. So, be true to yourself, acknowledge your real capabilities, set realistic goals and find yourself a good Pronunciation teacher.
Good luck and thank you for reading!