Most breeders log are notebooks. There are also computer programs out there is you want to spend the money. One you will need an ID system with your chickens and a way to set up breeding pairs or trios. You will keep a log on which hens lay most often and which ones are closest to standard for both hens and rooster. One you have chozen breeding pairs then you will be tracking offspring from them and how they develope. Growth rate, faults color ects. For ID system many use bands some use feathers by maring them if they can but bands or better and they come in colors.
