Assuming you're finding multiple sources that seem generally relevant to the topic, here are some considerations for prioritizing which sources to investigate further:
• Author & Their Expertise
- What is the author's connection to the topic? Are they an historian, a political scientist, or a scholar from another academic discipline? An activist?
- If you don't recognize the author (which is perfectly fine!), you could search for them on Google to see if they teach or taught at a university (which department are in they in?).
- For an edited volume - a book containing chapters that are each written by different authors - you could look into the editor(s) of the volume, and/or the author(s) of the specific chapter(s) that interests you most.
• Publisher: Where was the article or book published?
- Book -- Was it published by a university press?
If not, what can you find out about this publisher? Some publishers that don't have "University" in their names nonetheless publish scholarly books, such as Routledge, Ashgate, and Wiley.
For a book, you might also ask if the publisher focuses more on scholarly publishing, popular books, or more politically-oriented work? These lines aren't always clear, for example, Verso Books is an explicitly political publisher, but it regularly publishes books written by scholars who build their work on earlier scholarship.
- Journal Article -- What journal was the article published in?
Sometimes this is labeled as "Publication" or "Journal Title."
In Historical Abstracts and America, History and Life, the journal title is listed right after the author's name - look for Radical History Review in the image below.
• Scholarly Reception - How does this book or article fit into the larger scholarly discussion of this topic/question?
As a start, look for citing articles in Google Scholar. You'll get a rough estimate of how many times this work has been cited in other books and articles. (This doesn't mean that all of those citations were positive, however!) You can also see what kinds of works have cited this book or article.
You'll see 10 other works citing this article - some may be relevant to your work.