Wikipedia is an online, collaborative encyclopedia. Like all encyclopedias, Wikipedia is a great place to begin your research. Encyclopedias provide concise introductions to topics and can help you better understand your research topic and lead you to your research questions.
The Wikipedia project is grounded in five "pillars", which include a commitment to providing free content, fostering respect and civility within the community and maintaining the ability for anyone to add and edit information contained on the site. It is this last principle that makes Wikipedia a controversial resource for academic research.
Wikipedia's radically egalitarian content creation policy has garnered the project many supporters and detractors. Supporters often laud the open and collaborative approach taken to knowledge creation, while detractors express concern over the verifiability of information included in articles and the accountability of authors to the changes they make.
When it comes to using Wikipedia for your research remember that anyone could be writing anything (accurate or not; verifiable or not) in any article, and that most people writing articles are pretty knowledgeable about the topic and care deeply about what they do. In other words, feel free to use Wikipedia and trust that what you're reading is probably pretty accurate, but at the same time cast a critical eye towards any information contained on the site and do your best to back it up with scholarly evidence for your papers and assignments.
Remember, an encyclopedia (of any kind) is not the kind of resource you pull citations from and use to back up the arguments you make in your assignments. Rather, encyclopedia articles--like Wikipedia articles--are used to provide you with a good introduction to your topic, and provide a spring board for further research.
So go ahead and use Wikipeida in your next assignment, just be sure to back up any claim you make with well researched, scholarly evidence.