One way to evaluate an article is to consider where it is published. Scholarly Journals are the gold standard for publication in many fields because of their more rigorous peer review processes. Conference articles may go through some peer review processes, but these are often less rigorous than those followed by journals. The reputation of a journal is also worth consideration, and is indicated by its impact factor. Links to resources that will help you evaluate these aspects of the publication are given below. Other considerations include how current the article is, and whether the authors are authoritative and unbiased. You can find much of this information in the bibliographic information for the article found in the databases.
Once you find the right articles for your research, you will want to cite them appropriately. The rest of the resources on this page will help you to this correctly and efficiently.