Find publishers. Many Christian publishers are independent publishers and don't require an agent. Even Zondervan, one of the largest Christian book publishers, still accepts unsolicited book proposals. Check out the list of Christian book publishers at publishingcentral.com or the latest copy of Writer's Digest.
Request and follow submission guidelines. If you've already written the book, you'll still have to send a book proposal. A book proposal outlines your idea, your platform (your built-in audience) and your marketing plan for the book.
Submit your proposal and be prepared to wait at least six to eight weeks for a reply.
Choose your printing and distribution options. Most people looking to self-publish choose to use a POD company such as Lulu or Authorhouse. Christian-specific companies, such as Xulonpress.com, are also available. Crunch the numbers for each option and consider the distribution choices they offer. CreateSpace and Lightning Source are other POD printing options, but are not author-services companies.
Edit and lay out your book. If you don't choose an author-services company, you'll need to get these services elsewhere. There is a range of freelance editing rates, so shop around and be sure to work with someone familiar with Christian nonfiction. You can hire someone to lay out your book for the printer, or you can learn to do it yourself with "Perfect Pages," by Aaron Shepard.
Design your cover. Unless you're a graphic-design student or professional, your best bet is to hire a cover designer. To save money, look for graphic-design students. Art students at Christian schools might better understand the nuances of your book.
Submit your files to your printer and distribution channels. If you've chosen to work with Lightning Source, they have several distribution channels available. Whichever POD printer you've chosen, make sure they can get you into Amazon.com.