Fiction writers have dozens of places on which to market their books: book review sites, email newsletter blasts, and even genre clubs that promote fiction reads among themselves. Non-fiction writers can have the same results. The number of sites that take relevant non-fiction content is substantive, yet non-fiction writers do have to be a little more creative when it comes to their book marketing plans. 
Marketing yourself as a subject expert is a big part of non-fiction promotions. When people see you as the go-to person in your particular niche, they trust your expertise and buy your books. So non-fiction promotions is often more about you than the words you write. One great way for readers to get to know you is to write articles in niche magazines to show your expertise.
Why Write Elsewhere?
If your readers are really interested in your subject manner (and your best, most loyal readers will be), they'll have already found niche magazines in their chosen topic. Readers see the people who write for those magazines as people in the know. They respect their knowledge and seek out their advice. Become one of them and you've automatically got a head start in the race to market your books.
Where to Write?
Niche magazines fill the shelves at really bit bookstores, and can be found virtually anywhere online. Pizza makers have Pizza Today, puzzle enthusiasts have Games, and quilters have Quilter's Newsletter. If there is a subject that has more than three people interested in it, there's a niche magazine to serve it. The trick is to find these publications, and that's where Writer's Market comes in. This classic annual catalogs hundreds of niche magazines, and shows you how to search for more. Check your local library for a free copy, or buy the online version for the best bargain.
Preparation
Read the magazine you choose. Read lots of back issues, not the current one. In fact, choose a pile of magazines and read lots of back issues for each one. There's a voice and a rhythm to every magazine, and you're learning about each one's sound. Once you think you have the editorial voice down for your first choice, brainstorm to create a list of at least five possible article topics you could write that might fit in. Find the article editor's name and send off an email, pitching your possible titles. Don't send all five, but pick the best two or three to start. Do the same with all the other magazines on your list.
Results
When you get accepted to write an article, write your bio with your book sales in mind. Make sure you mention a book title or two, and show where you can find your books, whether online or in bookstores. Readers who like your article will automatically look at the bio to see what else you've written. They're automatically predetermined to like the way you wrote your book, so half the battle is already won.
Keep the Faith and may the Force be with You!
