The second edition of “Mastering the American Accent” just became available for sale. You can buy it on Amazon or wherever books are sold.   It has a lot more practice exercises for syllable stress and word stress and sentence rhythm. These are very important skills to learn if you want to speak with a natural sounding accent.  Also, the audio is downloadable now.  (instead of CD’s).  There are three hours of additional audio.  All the vowel sounds of American English are covered in detail.