Barron's ''Training Your Pet'' books are for inexperienced pet owners who seek detailed advice on how to get started in keeping and training caged pets. These books describe and illustrate the correct housing and equipment, and advise on getting all members of the household acquainted with the newly acquired pet. Guinea pigs are docile, easy to care for, and are capable of learning tricks. This book advises on keeping healthy and contented guinea pigs, and suggests activities that will amuse both the pets and their owners. Color photos on most pages.