Every thing the bird has comes from the Genes, Color, Speed, Velocity, Depth, and Size, to name a few, plus all the faults are carried in the genes. So whatever you want to have or get it must be in the genes to start with.
The Genetic Books will explain how to get all the colors and color patterns that you want.
The Genetic Books won’t tell how to get good rollers, like getting good velocity, speed or depth.
The Roller Books explain a lot more on getting the proper roll you are looking for. But remember it has to be in the genes for it to appear. They explain best to best and so on.
Pensom book has all the basics from start to finish, all aspects you need to start with.
The other entire collection of books explains how to dial in on some aspect that is in the Pensom book.
In my opinion it is best to get the Pensom book first. (All the basics)
The Birmingham Roller Pigeon > by William Pensom
Then get any of the other Roller books.
True Spinning Roller II > David Kowalski
Winners with Spinners > by Graham Dexter
How to Breed Better Rollers > by Tony Chavarria
Key to Flying Competition Rollers > by Tom Hatcher
Breeding and Inheritance in Pigeon > by Axel Sell
Hope this helps some.