As with all safari destinations there are a number of different ways to book a safari to the Okavango Delta. Different booking options will suit different people and all have their advantages and disadvantages. None of these should be seen as a recommendation but might serve as a start for the traveller.
There a number of Tour Operators that operate out of Maun. They are generally fairly small and offer very personalised and knowledgeable service. Because they are based in Maun they have good links with local safari companies and have good ground truth of local conditions. For foreign tourists they may appear an unknown entity.
South African Tour Operators have been offering tours to the Okavango Delta since the inception of the destination. Often part of larger tour operators they can benefit from preferential rates.
Perhaps not as knowledgeable as Maun Based Tour Operators, Home Country Tour Operators offer peace of mind as they are often backed by legislated trip insurance, although this is not always the case. Some countries, like the United Kingdom, have some excellent specialist safari tour operators.
Most tour operators have some kind of internet presence. It is always worth seeking recommendations from friends and associates. Before using an Internet Based Tour Operator ensure that they operate out of a known location and that sufficient guarantees are in place to protect your trip.