Keep in mind, if your cousin cites a source you haven't viewed personally, you can only cite your cousin's report about the source, not the original source. You are telling your reader that you trust your cousin's analysis of the documents in question. You cannot claim that analysis as your own.
Think of it this way:
Your cousin cites an ancestor's will and probate record that you don't have a copies of at point A in your research. Initially, you can only cite your cousin's statement about the will and probate record, reminding yourself to look for at the court of jurisdiction with book, page numbers and file numbers as reported by your cousin. Your cousin's work is a derivative (abstract, extract or transcript) of the original. We do list your cousin's work on the research log since this is the source of the information you have at this point.
At point B when you have obtained copies of the records in question, you can transcribe the documents and accurately extract pertinent information, citing the image copies of the original court records on your research log. Be sure to analyze the document, listing what questions it answers and what new questions are brought to light.
Point C is where you would analyze and compare the information in the will and probate packet within the context of a broader record group search to evaluate the evidence and resolve conflicts that may arise.
When you believe you have completed a reasonably exhaustive search, you can move on to point D, creating the "proof argument". More on that tomorrow.
OTHER BLOG POSTS IN THIS SERIES
SOURCES: Who provided the info - Part I
SOURCES: Who provided the info - Part II
SOURCES: Who provided the info - Part III
Happy family tree climbing!
Your friend in genealogy.