So you've decided to write an e-book, but what do you write about. You don't want to write about something and then have no one read it, that would just be a waste of your time. This is a fear that most people face...but in reality, it's a fear that hardly ever comes to pass, and especially on the internet.
All you have to do is tap into your inner resources and find out what it is that you are passionate about and then write about it. If you love cars, then write about cars, if you care about the environment then write about the environment, and if you love making money online, then write about making money online.
You can provide statistics on just about anything like Medical Science, diseases, animals, religions, government, and anything you can think of.
You can write guides on fishing, baby-sitting, parenting, how to improve your inner self, gardening, computer, the internet, crocheting, knitting, stamp collecting, investing, food, coffee, tea, sugar, and the list could literally go on for several pages, but I'll spare you the agony.
Basically just share what interests you, (provided you're not breaking any laws, or helping others to do so) and you will have an audience. Now there may be a few situations where the audience may not be very large...but with so many people online, with different lifestyles, habits, interests, and personalities, that there is bound to be an audience somewhere.
If you are planning on selling the book, then you may want to do some research to make sure there is an interest big enough that will generate you enough money to make it worthwhile. Also you want to do some research on what is already written, just so you don't write the same thing again, but if you write from the heart, then the chances of that happening are very slim.
So if you have a story to tell, then tell it like it is and people will love it. Don't try and make something up and pass it along as truth, people might fall for it in the beginning but eventually they will catch on. Everyone loves a good story about someone gaining victory over some troubled situation, so if you have one, that is a good place to start.
If you're in the tourist industry, provide a simple map, show a sample of menus from different restaurants and so on. If you're marketing a product and describing it in detail, just ask yourself what would you want to know about this product or service before making a purchase, and then write from that perspective.
Always keep your reader in mind. Ask yourself the questions they might have and then answer them. This alone could turn your book into a masterpiece which everyone will want to read.