Your manuscript has just gone through the editing process and now it is ready for the next stage in pre-production: interior layout. There are three ways you can go with your layout.
1) Hire a professional who uses a program such as InDesign to create a finished, professional look.
2) If you know InDesign or are a quick learner of somewhat complicated design programs, do it yourself.
3) Do it yourself using Word or WordPerfect.
Hiring a professional is the best way to go as the finished product will have a great look, with headers, footers (if needed), fancy chapter headings (if desired), proper line spacing, hyphenation, and many other text styles that accompany books from the big publishers. However, a professional can be expensive and many self-publishers can't afford one. What should you do? Take the time to learn a design program? Unless you're very comfortable with InDesign (or other programs used for book layout), it can be a daunting task that produces a less-than professional final product. Many self-publishers, therefore, decide to use Word or WordPerfect. They work hard to create a nice look, save the manuscript as a pdf file and send it off to the printer. It can work, and the majority of customers may not notice the difference, although any book professional (and that includes book store buyers and reviewers) can pick out these books instantly.
Word is notorious for messing up headers, footers, and other text styles that are found in a long document. Other times, it may look great in Word but when you convert the file to a pdf, strange things can happen, text gets moved, headers go away, reappear pages later, etc. It can become quite frustrating. If you do decide to do the internal layout yourself, please avoid these pitfalls that we've seen in books we've reviewed:
Use a font that's so small most readers have to squint
Use a font that's so big it looks like the publisher is trying to cover up a short book with large text
Make your margins too small/too big
Use different fonts for dialog vs. narration
Use italics for a large portion of your text. We recently had a book in which the main character wrote frequently in a diary. Those entries were all in a tiny, italicized font. It was impossible to read.
If doing the layout yourself, go to a book store and study other books in your genre. Note what they do. Don't try to be so different/unique that you wind up ruining your book. There's a reason those books are fairly standardized - it's easier on the eyes. We see so many self-published books where the author/publisher thought they'd be different and tried to create their own style. There is a reason books are right justified. We had a book submitted that was left justified, the same as you'd see in a letter. It looked terrible. It was hard on the eyes, and it sure didn't make me want to read it. It was well-written, the plot was good, but it would have been a much more enjoyable book if it had been right justified. A customer flipping through the book in a book store is more than likely to put the book back on the shelf. It sounds like such a silly, small, detail, but the incorrect layout gave the book a very amateurish look. Add to that the enormous number of typos and I'm afraid that this particular book is destined to have lackluster sales.
You put so much time and effort into writing your book - don't ignore the final touches that will make a customer want to buy your book!