Not completely sure what a water refilling station business is...but i'd start with these steps:
1. Get informed! Determine what part of Africa you'd like to establish yourself in. Be warned, the diversity in this single continent is massive. Both the price for your service and/or product and the operating conditions for your business will vary wildly based on where you decide to operate. For instance, the day to day realities facing a fisherman in northern Morocco versus those that face a Ghanian musician or a businessman in Johannesburg differ substantially. The point? Do your research, choose a location, and try to understand it on it's own terms. The "Africa" most people imagine simply doesn't exist!
2. Get prepared! Write a business plan. There'll be many useful hubs on this topic, but I can't think of one off the top of my head. Have a search ;-)
3. Get funding! Calculate how much you'll need for your operation. Halve it. Then halve it again. An almost universal reality of business in Africa is the absence of customers with susbtantial disposable cash (by European/American standards), yet no matter what part of Africa you visit, life goes on - employment and "jobs" are the exception rather than the rule. Most people run thier own business - on a shoestring to boot. Don't underestimate the value of locals when it comes to showing you how to get much more from much, much less.
4. Get there! There's a plethora of books on doing business in a foreign culture, but nothing will prepare you for the actual thrill and challenge of being there and living it. Be aware of the impact that the image you present will have on your ability to conduct business. Even an item as simple as bottled water can vary hugely in price based on the image you present, your negotiating skills, and the area in which you purchase it - nevermind the impact of issues such as supply and demand can have on a product.
Be fearless, you will be fine. To fail at this enterprise will be much more interesting than never having tried - so go for it!
The best single resource I can point you to is www.mbendi.com - a great business resource for Africa in general. Check out their database of personal contacts or business opportunites section.