Don't think of information sources as "good" or "bad" - instead, consider whether they are appropriate for your research needs.
Wikipedia, for example, might not be appropriate for your research project on climate change, but if you're researching crowd-sourced reference sites, then Wikipedia will be an indispensable source of information for you.
Primary sources are firsthand or eyewitness accounts. They present the actual evidence of an event without any analysis or interpretation. Primary sources include diaries, letters, legal or court documents, laws, speeches, statistics, journals, original research documents, and the like.
Secondary sources analyze, interpret, retell, explain, or critique primary sources.
Tertiary sources index, organize, and compile other sources and are generally not referenced in academic research. This category includes encyclopedias, dictionaries, and textbooks.
Scholarly sources, such as journals, are written by the experts in the subject matter. They are often written for use by other scholars, researchers, or serious students of the subject. They often use language that is specific to that discipline. They usually include in-text citations or footnotes and a works cited or bibliography. They are often peer-reviewed, meaning the article has been anonymously reviewed by a panel of experts in the topic before it has been accepted for publication. They are usually published by a professional organization, research center, or scholarly press.
Popular sources, including magazines and news sources) are written for a more general audience, not necessarily experts in the topic. They are often written by journalists or others who are not professionals in the field. They are written in easy to understand language; they do not use technical jargon. Although they may have footnotes and/or citations, they are usually not as extensive. There may be little or no editorial review.
Professional/Trade sources are published for practitioners in specific fields. Generally, both the audience and the authors of trade publications are practitioners in the selected field.
Popular and trade publications are not better or worse than scholarly publications - each source must be judged individually and within the context of the information need.
Print refers to materials that have been produced in a hard copy. Examples include books, magazines, journals, and newspapers.
Electronic sources (or e-resources) are materials that are available in a digital format and may be accessed electronically. Examples include e-books, online journals, articles from electronic databases, PDF documents, and web pages.
Multimedia sources refer to images, audio, and video. These sources may be physical copies (CDs, DVDs, etc.) or electronic (streaming media, MP3 files, online videos, etc.).