I use two kinds of records in my hamstery. A pedigree and a hamstery diary. Both are important.
Pedigree
I keep a pedigree sheet like the adjacent photo on every hamster that I breed within my hamstery. Others that I don’t breed from do get on the pedigrees of their parents so they get recorded too. If there are more notes than will fit I sometimes use a second page.
Diary
The diary contains all the information about the hamstery in general. If I move a cage, if a litter is born, if I change food, if I reduce the temperature, it gets recorded in this book.
My diary is actually contained in two books. The smaller one is the history and the larger one is where I keep my weather printout. You can bet that if all the breeders in my hamstery suddenly stop having young at the same time, I am going to be looking at these books carefully.