Do you have a business that is or has been profitable?  If you don’t mind giving away the secret, put together a book and teach others how to start the same business.  This is best when your business idea, if started in other cities throughout the world, would not affect your business.  There would always be a chance of someone local getting your book, but this type of book usually sells pretty well, so it may be worth the risk.

Avoid writing and selling a book on how to make money just for the sake of selling the book – with no real proof that your idea really works.  In short, avoid writing and selling “money making scam” books.  You might sell some books in the short run, but in the long run if your plan really doesn’t work you are doing a disservice to the public and it will ultimately fail.  Sell a high quality business “how to” book and you will do and feel much better.

Is there an aspect of your favorite hobby that you could write about?  One great thing about writing about your hobbies is it is easy to find and reach the market through magazines, mailing lists, etc.  If you’re new to a hobby and are learning about it, this could be a good opportunity to write a beginner’s guide to a certain hobby.  Then, once you are finished you will not only have the basics down, but will have a finished book ready to sell and told from the perspective of a beginner.

Is there a hobby you have always wanted to get into but haven’t found or couldn’t justify the time?  Now you don’t have to feel guilty.  Get into the hobby and write about it.

Study the market of the hobby you are interested in.  Check the Internet newsgroups and message boards.  Is there a recurring demand, need, help or want?  Get a feel for the market.  What kind of book do you think they would want?  What problem needs solving?

Here is a partial list of hobbies you might consider writing about, getting into and studying further: astronomy, birding, candle making, dumpster diving, gardening, home brewing, kites, remote control airplanes, magic, photography, rockets, trains, woodworking, rocks, models, soap making, treasure hunting, sewing, beading, ceramics, painting, leather work, wine making.

When you read, take notes of any ideas that pop into your mind.  It is a good idea to get into the habit of reading something every day if possible.  One idea or concept you read in one book might apply to another idea you have been working on.  What you read in one place might trigger the much sought after “Aha” experience.

Read on many different and diverse subjects and you will have a more creative outlook on things.  Don’t stick to reading just one subject.  Try to read at least thirty minutes or more a day and read on different subjects as well as subjects you specialize in.

Ask experts to help you find book ideas.  Ask librarians and book buyers at specialist book stores.  Ask if they know in which fields new books might be needed.  Do you know of experts that might live near you or someone you are interested in interviewing?

Perhaps they can give you more advice on what topics to write about and what topics not to write about.  If you have already decided on your topic, interview experts to get more specialized information you might not find by researching.

Keep your ears open to conversation between you and others as well as conversations you might overhear at work, at play or wherever you may be.  You may hear remarks from friends, neighbors or social gatherings that will lead to an idea.

Where have you traveled in your life?  Are you planning to travel in the future?  Does your job require you to travel?  Could you give advice to people traveling to the same destination that would improve the quality of their trip, save them money or maximize the quality of their trip in some other or combination of ways?  If your job requires that you travel frequently, perhaps you could write a book on your time off and kill two birds with one stone?

Is there a more specific aspect of a place you like to travel frequently that hasn’t been covered?  Is there a good selling book on a specific aspect of a travel destination that hasn’t been covered in a different travel destination that you could cover?  Take a look online and in the bookstores to see what travel books are offered.

One thing you might notice when traveling somewhere else is how people do things differently there than where you live.  It is amazing in the age of computers and the Internet how long it can take ideas from one area to reach another.  This is something to consider when writing a travel book.  Are there any ideas from one location that you can borrow to use in another place you are writing about?

Are there local travel books sold where you are visiting that are unique from ones you might find in a bigger chain book store?  What ideas can you borrow from where you are visiting?