Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Learn to make near PhotoRealistic textures by hand

This book is very good, to my knowledge this is the only book that teaches usefull textures and many realistic effects such as wood, rock, metal, leather, coblestone, bricks and many more. If you want to be able to make textures by hand without cheesy plugins, this will start you out and almost perfect your skills.