Ask yourself these questions:

nWho wrote this? Is the author well-known? Is there contact information for the author? nWhere does the document you found on the Internet live? Is it attached to a viable organization, library, university, or government agency? nIf the document contains research, does it include the data and an explanation of the research method used to gather the data? nIs the information timely? Is there a copyright date or a “last updated” date?