I have been keeping a composition book for three years.....each page is a month, and each line is the day of the month. It has been working great for me, as I can flip back and compare quickly things such as weight gains, growth,matings,# of eggs laid, feeds;what kind of prey and how many, and other items such as hatch dates, and acquired dates. It also helps me compare year by year and month by month.In addition to that, i have a reference folder for pictures, and pages of info I have printed off the computer.....such as YB comparison pics, Adam's breeding calendar, vet info/bills, and business cards from vendors at reptile shows. I keep records handwritten in a notebook because I totally suck at stuff on the computer....Do whatever is easiest and works for you....