There are different ways to organise references and attributions including: footnotes, bibliographies, or academic referencing (using a specific system, for example Harvard). The most important thing is to keep accurate notes and consider the requirements of your readers.
When it comes time to submit your manuscript to a publisher, the issue of attributions will be crucial, so find out what you need to know at an early stage in your research. If you leave it to the point of submission, you could be in for some re-working of your manuscript.
The way you reference sources will vary depending on the type of book you have written, the extent of the research that has gone into it, and the expectations of your readers. Historical fiction does not need the same amount of referencing as a non-fiction history book. Some recent historical fiction titles such as The Confessions of Frannie Langton mention primary and secondary sources in the acknowledgements.
A business book would require references to primary and secondary sources so might benefit from more formal referencing. At the very least there should be a reference section for further reading, and acknowledgement of the influences of these works.
Keeping good notes
One of the most frustrating parts of writing a non-fiction book is trying to find attributions for information that you have included in an early draft.
Imagine this scenario: in the first week of researching for a book you find a useful quote and include it in an early draft. Four months later you are finalising your manuscript and see the quote. With detailed notes it will be easy to reference the source, but if your notes are not comprehensive or disorganised you might to spend hours finding an attribution or even delete the quote entirely.
A bibliography is a list of books and other sources that the author has consulted when writing. This allows interested readers to find out more about the topics that have been covered. A bibliography is particularly appropriate for nonfiction books that appeal to a general reader.
Footnotes and endnotes
Footnotes are small notes at the bottom of a page of text that shows where information originated, and can also be used to expand on information such as providing additional context or description.
Endnotes put sources and references either at the end of each section, or all together for all chapters at the end of the book.
It’s most useful to readers to put information on the same page (as a footnote) where it helps the reader to understand as they are going, whereas sources are better placed as endnotes so they don’t distract.
Check the house style and advice of your publisher (if you have one) first to save confusion.
Academic referencing puts sources in a set and more detailed format in a section at the back of the book. This is is essential for texts with an academic audience. Seek out a style guide for your preferred method of referencing as many exist. There are transatlantic differences too, so it’s normally advisable to use a system that best reflect your audience. Note that some publishers may prefer a style, and this house style should be adopted from the outset, otherwise valuable time and energy will be wasted converting from one to another.