Several years ago I took an online course on Mastering the Genealogical Proof. We used the book by that name, Mastering Genealogical Proof as our text book. The author of the book is Dr. Thomas W. Jones, PhD. He is a noted genealogist and educator whose books focus on the methodology of genealogical research. The book teaches you how to recognize and evaluate sources for writing genealogical proofs. Each chapter is set up like a lesson with problem solving questions to help you understand the content. His book is for any researcher who wants to up their game and take their research to a higher level. I got a lot out of this book, the online class was an added bonus, working alongside other students raised the bar and made a tremendous impact on my research abilities. If you are looking to better understand sources, how to differentiate the quality of source types and fine tune your ability to write a proof, then I highly recommend this book.
One of the things I learned how to do during this course was to write source citations. The book we used as our guide is Evidence Explained by Elizabeth Shown Mills. This book is the gold standard for source citation. Now writing citations is no easy thing, each type of evidence requires a different style of citation. With many sources no found online the citations become even more difficult. Elizabeth Shown Mills breaks down each type of evidence and givens ample examples of citations for any source you can imagine.
One of the problems I had when I first started doing genealogy research was not being able to locate my sources once I'd moved on. Someone would write and say how do you know that, where did you find that? And I couldn't remember. That is where a well written citation comes into play. With an excellent citation you can always find your evidence. I highly recommend this book to every researcher who takes their work seriously. I personally bought the hardback edition. There are so many pages that I thought it might be difficult to find what I was looking for in a digital edition.