Another thing to consider is how easy it is for you to find this information. Typically, a reliable resource will make it pretty easy for you to confirm that it is in fact a good, credible resource. If you find yourself searching for a long period of time, that could be a sign that the resource you're looking at is not a good one for your academic work.
We're covering the most common basics of print and web here. There may be other avenues to the information you need that aren't covered. Remember that you can always ask your professor or a librarian for help determining whether or not a source is credible.
For our purposes here, we're talking about the 2 main print resources you'll probably be using in your classes for research. If you encounter another type of print resource, feel free to ask your professor or a librarian how to tell if it is reliable or not.
Look for publishing, etc. information on the first few pages of the book. This is typically called the Copyright page (though it won't be labeled as such) and looks something like the image on the left here. (HINT: A lot of the information you need to cite a resource can be found on this page). This page will give you information about the book that you can use to find out more about the publication. Particularly, note if the book is published by an academic press (ex: University of Alaska Press), which generally have higher standards for publications than non-academic affiliated publishing companies. Books published by academic presses are very good as far as published books go.
Publishing companies typically have a dedicated website these days that will give you an idea of whether or not it's an academic or popular publisher.
A quick web search on the author's name will often lead to a website, or at least some mention of any affiliation with a university or other reputable institution.
These days, periodicals also typically have a website dedicated to the publication that contains easy access to background and publishing information. It will also help you to know that there are different types of periodicals with different missions. Our library guide: "Periodicals, Journals, Magazines, and Newspapers: What's the difference?" can help you understand the different types.
Web resources are arguably the most difficult to find information on. If you're lucky, your website will have a very clear page of information about it that will help you evaluate whether or not it's a good resource. Any of the following may contain useful information about the website you're looking at:
Often these are very easy to find as choices or via a dropdown menu towards the top of the page, but sometimes they're more hidden. You may have to scroll to the bottom of the webpage to find a path to this information, or to the Sitemap which will give you the layout of the entire website. Some websites have a search engine for the website itself, and you can try this as well, though the reliability of those results varies widely.
Remember, web searching lures us in with how easy it is, but it does not promise reliable (or even relevant) results. There are ways to make your web searches more productive, including utilizing Google Scholar and learning to organize your searches to filter out less relevant information. The library has several guides that may help you use web resources, including: "Searching the Web Effectively: The Burrito Equation" and "Using Wikipedia for Academic Research". However, rather than relying on web searches, use the library discovery service as your primary place for academic research.