According to Google Scholar's "About" page, you can search across many disciplines and sources: peer-reviewed papers, thesis, books, abstracts and articles from academic publishers, professional societies, preprint repositories, universities and other scholarly organizations. Google Scholar helps you identify the most relevant research across the world of scholarly research.
So what does this have to do with you, the family historian? Everything. This is yet one more tool that can assist you in searching for information about your family. Now it's true, you probably won't find information specifically on your surname, but when researching you should be looking at the era that your ancestor lived (to better know what other resources would be available to you); the community; and aspects of their lives such as occupation. Remember, these scholarly articles are going to be by historians, those in the field of religion, economics, etc. -- they are going to be histories that will provide you more understanding of your ancestor's time period and life experiences.
Now in some cases, the articles might be available through journals or services that are subscription based. That's okay -- just jot down the title of the article, author, publication title, volume, number and pages. Then go to your local library and explain that you need an interlibrary loan on an article. Basically, they can then find the article and ask a library that has that journal to copy the appropriate pages for you. In some cases, your library, especially university libraries, may provide access to a journal database that is free to use onsite.
From the Google Scholar page you can type in the phrase or keyword that you are interested in searching. If you prefer, you can click on the link, "Advanced Scholar Search" and limit and define your search more precisely. Advanced Scholar Search allows you to choose an exact phrase and what words to leave out of a search. You can even specify articles written by a certain person, in a particular journal, or in a specific time period. If you want, you can even tell Google Scholar what academic fields you want to see articles from. This can be good when using a term like "genealogy" which can have meaning in other fields like philosophy and biology.
I conducted a search on Google Scholar on the subject "Coal Mining" and "Coal Mining History," and below I've included some of the results. All of these articles would provide some great background information on an ancestor that would help you better understand their life as a coal miner.
[BOOK] Coal is Our Life: An Analysis of a Yorkshire Mining Community. N Dennis, F Henriques, C Slaughter - 1969 - Tavistock Publications Ltd.
[BOOK] History of the Coal-mining Industry in Ohio. DL Crowell - 1995 - Ohio Dept. of Natural Resources, Division of Geological Survey.
[BOOK] The History of the British Coal Industry. MW Flinn - 1984 - Clarendon Press.
[BOOK] The Coal Industry of the Eighteenth Century. TS Ashton, J Sykes - 1929 - Manchester University Press.
[BOOK] Where the Sun Never Shines: A History of America's Bloody Coal Industry. P Long - 1989 - Paragon House Publishers
[BOOK] Economic Development of the British Coal Industry, 1800-1914. BR Mitchell - 1984 - Cambridge University Press
As you may have noticed, the results I show above have a [Book] tag in front of them. This indicates that the item is a book, and if it is linked it will take you to the book in Google Books, where you can read it or download it and save it on your computer. In some cases, the results will take you to a journal's online home, where you may need to a subscription to view it. In other cases there may just be a title and links to see who have cited that publication, related articles and related websites. If the title of the publication is not "linked" that means that the actual document is not online, so you will need to access it through interlibrary loan or through a library database. To learn more about what each part of the Google Scholar result means, check out Understanding a Search Result at Google Scholar.
While Google Scholar is not specifically a genealogical source it can definitely help you gain some knowledge about your ancestor's occupation, religion, circumstances or era.