I've answered a large amount of questions and I thought I would submit those answers here. These answers should resolve your questions, contact me at my talkpage if this page hasn't answered your question(s).
Users and administrators: Feel free to suggest this page to new users.
There are several ways you can help Wikipedia and one of them is starting articles. You can start articles if you're an expert of that subject (science, business, medicine, etc.). However, it would be helpful if the articles are sourced. To ensure you're familiar with the guidelines, the following links may be helpful: Wikipedia:Writing better articles, Wikipedia:Your first article, Wikipedia:Notability and Wikipedia:What Wikipedia is not. You may wish to start articles listed at Wikipedia:Requested articles and Wikipedia:Most wanted articles. If you're interested to fix articles, consider visiting Category:Articles needing cleanup.
When editing, I suggest using "show preview" (located near "save page"). Users should use "show preview because it will:
If you've come to Wikipedia to start an article saying "how fantastic of a cook your friend is" or "how cute your best friend is", please submit it to other websites (Facebook, blogs, Twitter, etc.). Wikipedia is for serious articles such as populated places, oceans, historic battles, etc.
Per Wikipedia:Avoid mission statements, avoid adding mission statements to articles. They aren't significant to the article and may be considered as advertising. Wikipedia is an encyclopedia, not LinkedIn.
Citing sources plays an important role at Wikipedia and helps verify the information. You can cite sources such as newspapers, books, interviews and magazines. With URL links, you may simply add <ref> and </ref> at the sides of the URL link.
You can also use inline citations with newspapers and magazines. Inline citations are details you can add to the references (publisher, date, journalist's name, etc.)
Example: <ref>((cite news| url= http://latimesblogs.latimes.com/lanow/2012/05/us-hikers-iran-married-in-california.html |title = U.S. hikers who were held in Iran are married in California |author = Scott Glover | publisher = ''[[Los Angeles Times]]'' | date = 6 May 2012 | accessdate= 7 May 2012))</ref>
Adding inline citations prevents link rot such as the page has been moved or deleted. With inline citations, it is possible to recover the article using these details.
Attempt your best to cite sources that won't require registration or payment such as payment-only news articles. If there are other equally informative and notable sources, use those.
For the references to appear, you must place ((reflist)) under the "References" header.
If a URL link isn't available but you have detailed information, use the same process as you would with references tags. The following is an example how you would reference an interview with no URL at Ben Kingsley.
<ref>June 2010 Parade interview, page 6<ref>
You may also use the same "inline citations" reference tags as shown above and remove the "url=" column.
Although users submit images to articles through HTTP links, it is preferred that the images be submitted through Wikimedia Commons. Starting a Commons account consists of a password, username and email address (optional). Including an email address would be helpful in cases of password recovery.
When submitting images, choosing the best titles is helpful. If the image is of a tree, the title should be either the name of the tree or its location (example:Willow tree at Barcelona museum). Images should not be titled "224666-mycomputer.jpg" as this may be challenging for visitors to find. For details, see Wikipedia:Uploading images.
If you are not a fluent English speaker, there are other Wikipedias that are listed here. There are Wikipedia websites such as Spanish, Italian, Japanese and Arabic. If you are learning English, there is also Simple English Wikipedia. With Simple English Wikipedia, articles are featured with the simplest content for users learning English.
It is understandable for users to get furious when their articles are deleted. However, threatening users won't help the situation. It is often better to either talk with them or ask for assistance at Wikipedia:Help desk or Wikipedia:Deletion review. Wikipedia is intended to be a website where users can be free and feel comfortable contributing. User or legal threats can damage the community and cause the situation to worsen.
Users are discouraged from adding "Mr", "Ms", "Mrs", etc. to articles or their titles per Wikipedia:TITLE#Common_names. Example: Mr. Johnny Depp is an American actor. Articles should contain a common title and it is unlikely that they were born "Mister" or "Mrs". Example: Elizabeth II's article title is not Her Royal Highness Queen Elizabeth.
Although users may use their talk pages for messages, the talk pages are not for unnecessary chatting such as:
John: Hello, Alexander. Alexander: Hey, John. Where are you from? Alexander: I'm from Wisconsin, you?
Please use email, Facebook, IM, etc. for such messages.
Although Wikipedia is among the most visited websites, Wikipedia is not a social networking website.
To change your username, see Wikipedia:Changing username.
Unfortunately, Wikipedia can't delete your username. However, you may: leave your account as is or you may add ((retired)) (I suggest using "retired" when you have an existing talk page and contributions).
Although users may find them amusing, joke articles such as people born in the 24th century should not be started. If you wish to start joke, please use other websites (Facebook, Twitter, blogs, etc.). Not all users are going to find your jokes amusing.
You shouldn't remove content that you may not agree with (religion, politics, nudity, etc.). Wikipedia is not censored and may contain information that viewers may not agree with. However, if the content is vandalism, feel free to remove it immediately. You should NOT remove maintenance templates if the issues have not been resolved, rather consider fixing the article. Template removers may and will be blocked if persistent. With these cases, it is essential that you use the summary box when editing.
If you are not an administrator, you shouldn't place protection tags to articles. If you wish to protect a page, submit an entry at Wikipedia:RFPP (guidelines to submitting entries are located at the link). Administrators are the only users that can protect pages, and will only protect pages if a significant amount of vandalism has occurred.
Per Wikipedia:External links, social links such as these aren't generally used as an external link if they can be accessed through the subject's official website. If there isn't an official website for the subject, you may use Facebook and/or Twitter.