Breeding Guppies: Genetic Pitfalls and Successes (10 page article) describes my experiences with crossing various guppy strains–Metalheads, Blue Grass, petshop guppies, swordtail guppies, etc. Avoid the genetic problems I encountered as a beginning breeder. Follow the story, which includes basic genetic explanations, to a happy ending–the creation of novel and beautiful phenotypes.
Guppy Genetics 101
Genetics of breeding fancy guppies for fitness, disease resistance, and beauty