Libraries, colleagues, professional associations, government agencies, your professors, and other resources all should play a part in a truly effective research process. Anyone with access to an Internet server can put pretty much whatever information they like on the net. Other resources tend to be much more reliable and authoritative. For example, librarians perform formal collection development to insure the quality of materials that they bring into the library. Articles published in scholarly journals undergo a rigorous process of peer review to insure the quality of published research.
Publishers have reputations for integrity in producing materials that are useful and trustworthy.
While not every book in a library or every article in a journal is always absolutely trustworthy, you can at least be sure that unbiased minds have checked on the information source before making it available. No such assurance lies behind information on the Net. This can be a good thing. Censorship is very difficult. Information disseminates freely and quickly.