Bellson, Breines book, Modern Reading in 4/4 - for all instruments contains exercises for sight reading and shows how any instrumentalist can improve their knowledge of rhythms and in our context, the drum kit.  The book is a vast and thorough text book that is the perfect resource to improve, and enable one to become a proficient rhythmic instrumentalist.  From West London Drum Tutor, Drum lessons in Harrow, London  http://paltip.com/westlondonenglish/!526w