Africa is an extrememly photo-opportunistic continent. From panoramic scenery, wildlife and birds to people and vibrant ceremonies. Rich colour and good low lighting conditions abound.
It is considered rude to take pictures of people without asking them first. Always carry enough film as it is difficult to get in some remote places.
Keep your cameras in a dust resistant, padded case and out of the midday sun. A 200 mm (or longer) telephoto lens will prove very useful on safari.
Camera film and batteries can generally be obtained in any major city or town. But of course the further away you get from civilization, the likelihood of availability decreases - like everything else.
So make sure to have sufficient supplies for your needs prior to embarking on a long trip.