I used to use iHerp but I stopped because its so much easier for me to use a notebook.
I have a feeding sheet for each snake, and i make a list of scheduled feeding days, and put a check if they eat, an X if they refuse, and an S if i deside to skip them that week.
I also have a sheet for shedding, I record the date they shed on, and then put their weight next to it.
I also have another section for general information, name of the snake, morph, date of birth, date of purchase, who it came from, and i give them an ID number.
And then another section for health, in case anything arises.