Well, the projects I have been running have all been based on either wifi or xDSL. So I can pretty much only provide my expertise in these areas, BUT......
I see a couple of possibilities:
1) Contact the preexisting DSL provider in your area, and tell them that fiber is now available in the area. Ask them if they would be willing to provide a new DSLAM in the area connected to the fiber, which would boost the speed of the internet considerably (if the DSLAM is within a mile or two you should easily be able to get a stable 20 Mbit connection, which I assume is better than what you have now). Its always easier to lobby someone else to do the job they're supposed to, than it is to start competing with them......
2) Contact the people providing the fiber and ask them what servicepartners they have that are last-mile providers. Contact some of them and ask if they would be intrested in setting up shop in your town. Get the local populace to sign a letter of intent, that they will switch providers, if they can get better or faster internet at the same or lower cost..... Again with the lobbying, but it's an easy way out
3) Consider setting your own lastmile service up. But use xDSL connections or wifi, because FTTH would require that you start digging fiber to each house. I doubt you could make a profit on that if you're a one-man operation. In a hilly area, get a permit to set up repeater antennas on the highest areas. I'm sure you have cell service in the area too, so ask the local cell providers if you could use their towers. Usually, they have the permits in place, and you'd just have to pay rent, or simply swap services with them (your internet for their towers), if you can find someone who'll go for a straight swap..... This option requires a lot of footwork, and negotiation, but it's possible even in an industrialized and regulated society, it's just a lot harder than in Africa ;)
4) Get a group of friends together and work out a division of labour, make plans and set them into motion... More people = less burden on the individual.
I'd say it's possible, but if the market was big enough that you could live of it, then I'm sure you'd have more than one provider covering your area at the moment. So dont expect to get rich in anything except experiences :D