I have learned by experience that what you found on the Internet yesterday may have a new web address (URL) today, or be gone entirely tomorrow. When I first began using Internet sources years ago I normally just copied and pasted the information into my genealogy program. If I was being particularly conscientious, I would include the Web page as a source of information — which is how I came to find out that Web pages addresses change or disappear altogether.
If you use Firefox as your browser, there’s an extension called Scrapbook which allows you to capture webpages complete, singly, or down to varying depths. It also includes simple editing tools for leaving notations and highlighting on the pages before or after capture, if you need to. Another paperless solution.