Over the summer I have been working on a notebook containing information for each of our foster daughters. I have five pocket dividers in my notebook - one for each girl.
I keep a list of doctors, the pharmacy number, school information, sports information, friends' numbers, and anything else that relates to that child. When I need to make a doctor's appointment, I just flip to that page to find the number.
In the pocket I keep business cards, receipts, prescriptions, schedules, etc., until I have a chance to document or use them.
I also have some notebook paper in each section to take notes when I go to the doctor, etc. I take the notebook to each doctor appointment so I have everything I need while there - pharmacy phone number, referring doctor, etc.
More on organizing information: