get this kind of question all the time, so I figured if I blogged an answer, I could just post a link instead of writing a whole new answer every time this comes up:
Thanks for your message. I don't think there's any way to explain in an e-mail message all that is involved in turning sermon transcripts into published prose. It's like playing the piano or being any other kind of artist: while you can teach almost anyone the bare-bones basics, a very large part of the skill set necessary for doing it superbly or professionally is inborn talent, not something that's teachable (or even explainable). All the best editors I know didn't go to school or take a course to learn what they know; they just have a natural gift for the work, and they intuitively know what to do. Even so, all of them would tell you it is grueling work, not for the fainthearted.
Furthermore, most pastors' sermons shouldn't be turned into print form. Sermons lose something important in the process, and even the greatest preaching in the world doesn't easily translate into great writing. (And unless you are already a superbly gifted writer, no matter how great the original material is, you'll never be able to translate it into writing in a way that equals its original greatness.) Preaching is very different from writing, and unless the sermon itself is very fertile with important thoughts and profound insights, it's probably not going to make a viable book anyway. Tell the average Christian publisher that you want to make a book out of a sermon series, and unless you are a preacher with worldwide fame and a following of untold thousands, the publisher isn't likely to be interested anyway, no matter how much the people in that pastor's flock appreciated the sermon series. Sermon series made into books don't generally do very well. There are exceptions, but few.
And even if you're working with some of the greatest sermons ever preached (something I have the wonderful privilege of doing) the labor involved in turning transcripts into prose for publication is quite literally a full-time job;and not a job I would recommend to anyone who can't devote everything to the task. Far more creative energy and ability is required than you could possibly imagine. It is literally harder and more time-consuming to translate someone else's sermons into written prose than it would be to write your own material from scratch. If you're dealing with John MacArthur's sermons, his material will certainly be better than if you wrote your own, but it's still no less work.
Moreover, if I were the world's greatest editor looking for freelance work, I would not propose to edit any preacher's material for publication unless some publisher is already demanding specific works from that preacher. If there's no up-front assurance that what you do will be published, I don't think it's a wise stewardship of your time and energies to do the massive amount of necessary work.
I'm sorry if that sounds discouraging, but I want to be totally candid with you. In short, my advice is this: I gather from what you say that you have no background or training for the work you are describingand if that's true, my best advice is to look for a ministry that gives you an opportunity to do something you already know how to do well. But even if you are a highly skilled and experienced editor, you shouldn't do what you are proposing at all unless you have the opportunity to work on a project that has already been embraced and committed to by a legitimate publisher. There are many more profitable ways to invest your gifts and energiesand still be a support and encouragement to your pastor.