If you make a caricature that looks like or looks nothing like what the person looks like you'd need to state who it is meant to be, so permission from that person in necessary. Photographs definitely. What is the content? If it involves writing by you get it read and corrected.
A disclaimer is good, but they are not always accepted, try to get all permissions in writing, preferably signed and with the name of the signing person.
Just think of it like this, that you make a living from your job and your looks. Then some person tries to make money from your looks, would you want a cut?