How to Promote YOUR book on Amazon discussion

My wife has published an excellent book, but, neither her nor I, are proficient at marketing or getting reviews for her book. Personally, I don't read novels that much as my reading consist of Science, Philosophy, or Informational topics, However, I have read her book through 3 times and have enjoyed it in all my reads. So to help my wife in getting the book in front of readers, I am looking for some advice. The book is a mixture of Romance, Science Fantasy, with a Christian theme. Any help/advice would be appreciated!!!!

If you are willing to spend some money, hire a marketer, but ask for recommendations from other authors first.
Tony