True confession: I never had a tree on Ancestry.com until a few weeks ago. (Back in the day, I uploaded my ill-sourced tree to Rootsweb Worldconnect.) So there was quite a learning curve, especially since for research purposes I did not want to start with myself, but to start elsewhen and work downstream.
When I finally did manage to make an entry, the software offered me the option of putting in a source. The obvious box to click is to search, which produced thousands of irrelevant results. It turned out that to put in an actual source citation, I had to go to a different screen. Even then, I had to put up with their assumptions about source citations.
You can share my experience if you pick a person in your Ancestry tree, go to their individual profile, then to "Facts and Sources." Select "Source Citations," and in that window click on "Add a Source Citation." In that window, under #1 pick "Create a new source." Or just click here. Or google a portion of the below-quoted text in quotation marks.
That window includes a block of instructional text. I finally got off the learning curve when I read it, and after I could draw breath again:
A source is a document, index, book, person or other material that gives you information related to a fact or event in your family tree. Sources can be original, like an actual document or legible image, or the [sic] can be derivative, like a transcribed copy. Original sources are considered more reliable because they provide irrefutable proof of a fact or event. [italics added]Golly. I remember holding an original birth certificate, quite soon after the event, stating that our newborn baby girl was a boy. Earlier this year I published an article about a fellow who gave three different names for his mother in three different original records. In each of them, he named as his father a man who died three years before he was born. Yeah . . . irrefutable.
Harold Henderson, "How I tried to create a tree on Ancestry.com and almost died laughing," Midwestern Microhistory: A Genealogy Blog, posted 24 October 2013 (http://midwesternmicrohistory.blogspot.com : viewed [date]). [Please feel free to link to the specific post if you prefer.]