Since I have several species of reptiles, my cards include species (subspecies as well if it applies), the common name (ball python as opposed to python regius), the nickname I have for the animal, as well as an ID number, the date of birth, parents if I bred the animal (the seller if I bought it), gender, a description of the snake (heaven forbid I mix up cards), and any special notes on the animal.
All of that goes across the top of my sheet, and underneath that information I draw a line, and then record meals and size of prey, whether it was live, prekilled, or F/T, sheds and the quality of them (dryest part of my year is in December and August, I've found), occasional weights, and any significant events such as breeding introductions or visits to schools.
It sounds like a lot more work than it is - once you develop the habit of jotting down a note, it comes easier.
I also have a copy of a generic animal pedigree program that I enter in old cards with. I don't think it was originally intended for use with reptiles, but I make it work.
I also keep track of all of this information for the entire time I have an animal. I didn't always keep track, but I have been for the past couple years and it's been the best thing I ever started doing.
Hope that helps!
~jenny
-----
"Polysyllabism in no way insures that what you're saying is actually worth being heard." - Blake (an e-friend of mine)
"I have never made but one prayer to god, a very short one: "O lord, make my enemies ridiculous." And he granted it." - Voltaire