Regardless of your ambitions as a photographer, you can never bring too much film. You will find an unlimited number of subjects to shoot: the beaches of Zanzibar, old charms of Dar and Stone Town, Mountain Kilimanjaro the animals and most importantly the people. Come prepared. with at least twice as much film as usual. Bring a range of ISOs. Much of the time you will be shooting in bright sunlight, so a slow film will be ideal. However, midday can produce harsh shadows; the narrow alleys in the old towns are always in deep shade; and you may spot that elusive leopard at dawn or dusk, so you will need faster film.
The most important piece of equipment is a zoom lens. When you are out on safari, the animals seems close enough to touch, but photograph them with a wide angle lens and they look miles away. A good zoom (up to 250-300 mm) will bring your photo to life. Avoid photographing anything that may be considered strategic such as bridges, police stations, etc. If in doubt, ask. Also be sensitive while photographing people.
The most delicate photographer's dilemma is shooting people. You would have to get far off the beaten track to find anyone shocked to a Mzungu (white man) with a camera. Some will want to pose, while others will run for cover; the more entrepreneurial will want money. The Maasai will make it extremely clear that unless they get money, anyone attempting a sneaky shot will be in trouble. There is no doubt that the best option is to get to know the people around you. While this may seem too big a task, Tanzanians are very friendly and generous and much easier to get to know than the strangers back home. However, there may not be time when blowing through a small village, in which case you must decide: photograph and ask or ask and then photograph.
Few Tanzanians are neutral about the camera's eye. If you take a picture without asking, you get more natural images but may face the subject's wrath. Some Muslims particularly women, may be genuinely upset. However you will probably be presented with the invoice of an open hand. If you ask first, it will prevent any possible insult and will mean you have some control over the price. However, if people say no, you must accept their decision. If they say yes, you will lose the spontaneity that first caught you eye. Often people will simply ask for a copy. If you agree and take their address,make sure you send them one. It will be a valued present.