This is an excellent and comprehensive book on Greek accentuation:http://www.amazon.com/Short-Accentuation-Ancient-Advanced-Language/dp/1853995991/ref=sr_1_1?s=books&ie=UTF8&qid=1394894831&sr=1-1&keywords=probert+greek
New Short Guide to the Accentuation of Ancient Greek by Philomen Probert
This book sets out the rules, which for the most part tend to be scattered throughout grammars such as Smyth.
You can also find a statement of the principal rules in Morwood's Oxford Grammar of Classical Greek, pp. 222-226, which does an excellent job of collecting everything you really need to know about ancient Greek grammar clearly, succinctly--and cheaply:http://www.amazon.com/Oxford-Grammar-Classical-Greek-Morwood/dp/0195218515/ref=sr_1_1?s=books&ie=UTF8&qid=1394896722&sr=1-1&keywords=morwood+greek
One suggestion: when you're learning an individual word, internalize the accent as a stress accent, so that when you think of the word you hear the stress on the accented syllable in your mind. In most cases, it will be clear whether the accent is acute or circumflex. This is only necessary with words other than verbs, of course, because verbal accents follow their own rules--mostly recessive, with a few exceptions which you can learn. Many nominal suffixes have accents on fixed syllables, which you will internalize over time.
One other suggestion: if your aim is to read real Greek, you could get by without a thorough knowledge of ancient Greek accentuation. After all, in general the diacritical marks weren't added to texts until long after they were originally written--at a time when the tone accents had long ceased to be operative, based on a tradition handed down in schools, and there probably many instances where the accent marks have found their way onto the wrong syllable. In fact by the Roman period there were treatises (such as Herodian) on accentuation to correct errors (and there's really no way to know whether these authorities really knew what they were talking about), which suggests that by this period there was some confusion even among Greek speakers. The diacritical marks were originally developed in the Hellenistic period for texts of Homer, and at first were only placed on obscure and difficult words.
There are some situations where the accents are helpful to resolve ambiguities--aorist optative vs infinitive, for example, but other than that, they are to some extent excess baggage for those who intend only to read, and not to edit, texts. Learners of ancient Greek might do well to consider whether the effort required to learn the accents could better be applied to other activities--especially to reading actual Greek texts.