Hiding some details from view- staff appraisals, etc

[aussiedentist]

Just wondering if there is any way of keeping track of staff notes on the computer?
I have them as patients, but then anything i write can be seen by everyone
I am horrible at remembering names and faces, and will be hiring and firing soon
I am thinking of putting in people i try out as patients, maybe with a first name such as "da debbie smith", put their photo in there, so i can write notes, etc
This should work brilliantly and i should be able to keep track of them.
I would like to be able to hide some info that can only be seen by admins

Any bright ideas?