I am about to set up a wifi network that would run for about 5km and would enable about 300 users to connect for highspeed internet access. please i need recommendation on the type of equipmenst to use and the amount of bandwidth to purchas I will be very grateful if anybody can help me.

WiFi does not have such a range normally. In any case, you will need a number of bridges/repeaters. You can send from one repeater to another over a long distance using a Yagi-Uda directional antenna. I've used them in the past to bridge local WiFi transmitters over a distance of 100's of yards to over a kilometer. Bear in mind that you may well violate federal (FCC) power limits using this technology!

commented: Short and to the point. +9

Exactly what the 'rubberman' said. When you asked this question i was surprized that how can we get the wi-fi routers or access points of such a huge range. Well, deploying boosters will surely help you.

Yagi-Uda antennas are truly awesome! Because of their tight directionality, they don't usually interfer with other radio transmitters/receivers. I taught a class once where we used one to link two facilities via WiFi that were over 1/2 mile (a kilometer) apart. The signal loss was negligible, and both facilities have "seamless" connectivity to the internet. One had the physical broadband connection, and the other did not. A colleague of mine uses these antennas to connect his house in Hawaii to a cell tower (with a nano-cell) so he can get cell coverage out in the boondocks where otherwise it would just be "dark country".

Also be aware of the curve of the earth, as this will come into play and distances like this.