Wikipedia is an encyclopedia which is free to use and edit. It is available in many different languages and on many devices. The content of Wikipedia is free to reproduce under the same licence, except for some images.
Wikipedia uses the minimum of censorship. Generally, only gratuitous explicit (pornographic) images are removed. The community of Wikipedia editors determine what text and images are displayed, so there may be material that offends some people. There may be those who are offended, shocked or disgusted by medical images, nudity, religious imagery and controversial images.
There is a search box in the upper-right corner of the screen, with the word Search in it. Just type what you are looking for into the search box and press ↵ Enter. See Help:Searching for more details.
Cite it as you would any other web page in accordance with the normal citation practice the publication you are submitting the paper to follows. Citing the individual authors is not necessary, but you should at least include the date on which you retrieved the article (and ideally the full timestamp from the history).
Automatically generated citations in several standard styles are available through the "Cite this page" link in the toolbox.
You should correct it. (See Wikipedia:Contributing FAQ.) Wikipedia is written by volunteers who believe knowledge should be free for everyone, and the community is always ready to welcome new volunteers.
Because Wikipedia is an all-volunteer project that anyone can edit, errors or omissions can and do creep in. This should be kept in mind when reading; the very nature of Wikipedia means it should not be trusted completely. Articles frequently contain citations of authoritative works where a reader can verify the information found.
If you see that something can't be right but are not sure what the correct information is, you can signal the problem on the article's talk page: click the tab labeled "talk" on the top of the page, and next click the tab "new section".
Wikipedia is funded by donations and does not display advertisements on articles. If you see ads, then something at your end or in between must be placing them. Some browser extensions or plugins can do it, for example, Codec-C and InfoAtoms. Codec-C is marketed as needed to play videos. Your computer may be infected with malware – consider using anti-malware software. You may be using an Internet access point (such as public Wi-Fi networks at some hotels or cafes) which injects ads into all kinds of web pages – try accessing Wikipedia via the encrypted HTTPS connection (e.g., https://en.wikipedia.org/wiki/Main_Page ). You may be viewing a mirror or fork hosted by someone else, not the Wikimedia Foundation, and that host may have added advertising and perhaps other content – verify that the whole URL in your browser address bar is for this website and not a mirror or fork, and if you're not sure then copy either of these addresses and find the content you want from it: https://en.wikipedia.org/wiki/Main_Page or http://en.wikipedia.org/wiki/Main_Page. There may also have been inappropriate user edits to Wikipedia which look like an ad or even claim to be an ad, but such edits are against our policies and not real paid ads.
Where can I get more information about using Wikipedia?