You need to critically evaluate ALL information sources, whether from the web, in print, your professor, or the library (this can be done at differing levels; you generally want to evaluate at a deeper level items you find on the open web). Ideally you want to make sure you are finding literature that represents a variety of viable (and potentially conflicting) perspectives on your topic. You also need to critically evaluate each piece of information you intend to use in your research for:
Reading Scholarly Sources
IMPORTANT: scholarly articles are written by and for experts. They are very narrow in focus. For example: you will likely not find scholarly sources about all aspect of something like "human services" or "counseling for abused children." This doesn't necessarily mean you need to change your topic. It does mean that you will often need to locate multiple articles that only discuss parts of your topic (for example, one article may discuss music therapy techniques for abuse children, while another may cover legal aspects of working with abused children), and then collect useful knowledge from those articles in order to understand and write about the broader paper topic of counseling abused children.