The answer is simple -almost any type.

With over 300,000,000 people online there's a massive potential market for all but the most specialised type of E-Books. The best advice I can give you about the subject of your ebook is to write about what you know or about what interests you, something that you would like to discover more about yourself. Personal passion about a subject shines through in your writing and makes for a more enjoyable read, entertain and educate your reader, deliver what they want and you will have made a customer for life.

Handy Hint: Do not make the common mistake of believing that your ebook should be about making money or internet marketing - In fact, it's much easier to generate a higher income by targeting your ebook at a more generalised audience or a non marketing niche, as opposed to the small proportion who are Internet entrepreneurs.

There are thousands of people interested in thousands of topics the secret is: Discover a need, target the market and feed it. A word of warning: Try to avoid fashionable subjects or subjects related to current news stories. You may find that what was searched for 10,000 times last month only manages a couple of hundred a month later and by the time your ebook and sales site are ready to go live you may find you have few or no customers.

Here are some excellent resources to enable you to find out what topics are hot now:

http://www.google.com/press/zeitgeist.html

Another method of establishing 'What Sells' is to visit the big guys and find out what they're selling. Check out the bestseller charts at

Amazon.co.uk
Amazon.com
Bol.com
Barnes and Noble

Once you have chosen a subject(s) you can proceed to the next stage of your research. To do this you will need to check out the overall levels of interest in your selected subject.

If your chosen subject hasn't generated many searches you may not be able to sell many copies of your ebooks. In my experience sticking with subjects that have generated at least a five to ten thousand searches is a safer bet, this way if you work on a small percentage of the total searches it will give you an idea of how many books you could potentially sell.

You should also at this stage search for other web sites that relate to your chosen subject. I personally find that the easiest search engine to use is Google.com

It's really important to find out before you start creating your book that the information you plan to sell isn't available for free somewhere else and this is also a good time to check for potential competitors, reciprocal link sites or possible affiliates programs you can join.

Make life easier by creating a spreadsheet and note the URLs of the sites and forums you visit, add helpful notes and comments about any interesting stuff you pick up along the way - This part of your research can be a little time consuming but it will be helpful as your business develops so take some time and immerse yourself in your chosen subject, believe me it will pay dividends later.

Every author when writing a book needs to conduct research and it's no different when you're writing an ebook. You have in front of you the best tool available to carry out your research - it's called the Internet and the best thing about it is that it's absolutely free.

Here are just a few of the thousands of research resources you can find on the web:

http://www.bartleby.com
http://www.brint.com
http://www.encyclopedia.com

If You need more information about e-Book business visit www.OnlinePassiveIncome.co.uk