When travelling most people want to take a camera along to record their trip. But its worth asking what you are recording it for. The down side is that you have to carry it, it can get stolen, broken and you can alienate the locals with it.
This is probably the most difficult area to cover and probably the most important if you care about the people in the countries you are visiting. In some countries the people believe the camera takes away the sole therefore you should always ask before you take anyones photograph. How would you feel if you were sat at work or on a park bench and someone came up and took your photo without asking? Some people may ask you for money in that case its up to you but ethnically it is probably better to walk away without taking the photograph. If you want to photograph a stall holder or similar try buying something from their stall in exchange for taking their photograph.
Some people will obviously ignore the above advice but be warned you may get chased and will make the locals more hostile to other travellers.
In many countries there are areas where you need to obtain permits to use a camera. Cameras should never be used near police stations, military installations or personnel, care should be taken around political buildings and anything that can be considered of tactical importance a less obvious example being dams and bridges. If in doubt ask its better than ending up being accused of spying.
Photographic permits are often only available in a countries capital city so its worth finding out if you can get one before leaving home. If there is more than one of you and you plan to spend some of the time apart make sure you get a permit each else you might be held until the permit holder is located. Beware in areas that photography is not permitted if your guide tries to get you to take photographs as there have been cases of people being blackmailed later. If this does occur probably the best cause is to expose the film to the sunlight so that the evidence is destroyed and they can't continue with their black mail plans.
So you are of for the trip of the life time what you need is the latest state of the art automatic camera. Well actually probably not like most gear you take on a trip the best equipment is actually the basic built like a brick shit house variety. Most people who are serious will choose a SLR 35mm camera if that is what you are after try and get an older metal body model which has less electronics and manual zoom. You will probably have to go to a good second hand camera shop and you'll have to spend time learning how to use it but it will last better and give you just as good photos as a modern fully automatic even if you'll have to spend a bit more time learning how to use it.
Automatic zooms are a pain especially in dusty conditions when the dust works its way into the mechanism. Electronics are also susceptible to continual vibration and temperature variations. Remember you'll need to take along spare batteries and that they may not function well in cold conditions. If the camera refuses to work in cold conditions try removing the battery and warming it under you arm for a few minutes.
For long trips its worth taking a second smaller 35mm camera. They are easier to carry on a daily basis, less obtrusive and give you a back up option. Again the more basic the better chance of its surviving the trip even if it means the pictures aren't as good as least you'll have some.
The biggest killer of cameras are knocks, vibration and dust therefore the first thing is to invest in a quality case and to keep the camera inside it at all times when its not in use preferably in a plastic bag. The catch 22 here is that the cases are an obvious target to thiefs so it should be kept out of site in a less obtrusive bag when out and about. It is possible to get camera cases with a steel wire running through the neck strap the idea being that a thief can't cut it with a knife these should be avoided as there have been cases of the thief strangling there victim or causing neck injuries trying to get the camera. If you are attacked then hand over the camera its not worth your life.
Be aware of its position when its in your main pack as its easy to forget its in there and dropping the back pack or hit a wall with it can be an expensive mistake. When travelling take the camera into the vehicle rather than leaving it in your pack sat on the roof.
Regular cleaning of the camera will help prevent it failing check you know how to do this before you leave and have any necessary cleaning fluids and tools.
The choice of film will depend on where you are travelling your camera and the type of photos you want to take. In general 'amateur' film is more tolerant and will last better than 'professional' film.
Films are sensitive to heat, light and moisture. Therefore it is a good idea to keep them in a sealed container, plastic sandwich boxes are ideal for this the film should be kept inside its own black plastic container when not in the camera. It is useful to attach labels to each film cartridge before you leave so you can mark the date they are used on. Keep a note in your diary of the area the photographs where taken in its a lot easier than trying to remember several months later where a particular film was taken.
One area where there is some dispute is wether its save to let your film go through xray machines at airports. Most seem to cause no problem but if you are in doubt customs officials may check them individually. The alternative is you can get foil bags that are supposed to protect the films in xray machines.
When buying film abroad try and do so in larger towns where they is less chance of it being left on a shelf for years, check if there's any sell by date and try and buy a well known brand.
Depending where you are it is usually possible to get a film developed. There are two main draw backs the quality of the developing might not be that good. The other draw back is that photographs and negatives are delicate and take up more room than a film cartridge. If you want to get films developed in the third world select a shop and let them do a single film first so that you can judge the quality of the processing.
Films can be sent home by post but its best to send them individually or to use a recognized carrier such as DHL to guarantee you don't lose your memories.