Here are some materials for pronunciation.
The international Phonetic Association. It is one of the oldest representative organization for phoneticians.
The CMU Pronouncing Dictionary. An online pronunciation dictionary offered by Carnegie Mellon University. It is a pronunciation dictionary for North American English that contains over 125,000 words.
Yahoo Pronunciation Dictionary. An online pronunciation dictionary. The vocabulary is provided by American Heritage Dictionary.
Merriam Webster Pronouncing Dictionary. One of the most famous dictionary in America. It provides sound for each word, which is good for learning pronunciation.