Wikinews articles follow a fairly strict structure designed to maintain a news style. Details and intricacies can be found in the style guide, but this essay is a guide to getting your first article on the road to publication and a place on the front page.
The three primary elements of a Wikinews article are the date stamp, the body of the story, and the sources section.  The easiest way to get these in your article is to use one of the boxes for starting an article, such as the one on the Main Page.  This will put in the all-important {{date}} template, add a section for your sources, and leave you ready to start writing.  Don't touch the date template, just ignore the odd looking code in it — this gets converted to today's date when you save the article.  Leave a blank line after the template and start writing, aim for at least three paragraphs on the story and don't copy from where you first saw the story.  The only items you can copy from a source are quotes, for example you could write:
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According to Reuters, President Beeblebrox said, "I love this ship so much I think I'm going to have to steal it."
In this way you're saying who got the quote and giving its text in quotation marks.
Keep the title short, but informative when filling in the box to start an article. Wikinews style for titles is all lowercase except the first letter and any proper nouns. So, "Beeblebrox steals revolutionary spaceship at launch" is correct, do not use "Beeblebrox Steals Revolutionary Spaceship at Launch".
In the edit box for your article there is a heading "== Sources ==". Underneath this you must detail where you obtained your information. This is done with the {{source}} template, which can be inserted by clicking on the *{{source|url=|title=|author=|pub=|date=}} link in the editing page. You will need to fill in the template with the web address of the story, the title, the author, publisher, and the date of publication. (To fill in, type or paste the information after the = symbol, and before the next | symbol.)
Always aim for at least two sources. This means you are much less likely to get into problems with copyright, and you have confirmation of the story from two places. Beware! When news agencies like Reuters or the Associated Press release a story many sites will list it. Watch out for picking two sources that say the article was written by AP.
The first paragraph of your article should do its best to answer Who, Where, When, Why, What, and How. This is where you are "selling" the article to the reader and trying to persuade them to read the whole thing.
Once you've got your opening paragraph in place you want at least another two paragraphs to flesh out the story and provide the details. Try to write two or three sentence paragraphs in preference to single sentence paragraphs; keep the sentences short for clarity, and check your spelling.
In general, a news article makes broader statements at the start, and becomes more specific further in. The last paragraphs are often 'backgrounder' information, to help the reader understand the context of the story.
Your article should now look something like the following:
Now might be a good time to save your story; there is more to be done, but these are the most essential details.
The above example is pretty bare-bones and would not be published as-is because there are a few more points to consider.
What you have now is an article in development. To make this clear to others on Wikinews add the {{develop}} template at the bottom. You can then work on all the following points to improve it. When you're happy with what you've got remove the {{develop}} template and put {{review}} at the top after the {{date}} template. This will prompt an uninvolved editor to review and check it, they will put a review template on the talk page and publish it if everything is okay. This means they'll remove the {{review}} template and put {{publish}} after the sources.
Do not try to go straight to {{publish}}! Technical measures stop unreviewed articles appearing on the main page and when your article is not properly categorised it may be overlooked, lost, and then deleted when it is too old to still be classed as news. (Wikinews axiom: Facts don't cease to be facts, but news ceases to be news.)
News is organised into categories, and you have to add these per the style guide. For the above story the most obvious is Category:Crime and law, so at the very bottom add
You should also have a geographic category.  In this case it would be the country where the crime took place, say Category:United States, as well as continent Category:North America, and possibly state Category:Alabama.
As a sister project to Wikipedia, Wikinews can link to their articles as a source of further information. In this case, they have an article on the Heart of Gold, Heart of Gold (spaceship). This looks pretty ugly in the middle of the article so instead you'd put the following:
The text after the second "|" is what will appear in the article, thus: Heart of Gold. The "w" names a template; it means the article should be found on Wikipedia if it doesn't exist on Wikinews. If you forget to use the {{w}} and instead use a wikilink, [[Heart of Gold (spaceship)|Heart of Gold]], the software will try to link to a local article (which, in this case, doesn't exist). Besides Wikipedia, there are several other useful sister projects that can be linked to this way, by adding another parameter |sister=project| to the template, such as {{w|sister=wikt|...}} for Wiktionary, an online wiki dictionary.  Another choice would be "sister=s", for Wikisource, an online library for public domain works. A complete list of wikilink shortcuts can be found here.
Sometimes you will want local links; after all, this is a news site.  Don't worry; just use {{w}}.  If the target page exists locally on Wikinews, {{w}} will link to the local page.  For example, {{w|Mumbai}} produces: Mumbai.
If you look around Wikinews, particularly at the articles up in lead positions, you will see a variety of visual elements used to break up the text and make the article more appealing. These range from the informational boxes down the right to images and pulled quotes.
Suitable images from Wikimedia Commons can be added to the article using this notation:
This appears as shown in the left side of this section.
A good place to put this would be the blank line after the {{date}} template and before the first paragraph.  Don't insert another blank line or you will end up with odd whitespace around the article.  This generally applies to all decorations — they replace blank lines between paragraphs.
Where you have a long article and several images you can change the "left" to "right" on some to balance up the article and avoid a lop-sided looking appearance.
Note the {{image credit}} template embedded within the link for the picture.  Wikinews has an unwritten rule about trying to credit the source for any images we use.  On the leads on the main page this is a link to the image page on Commons; within articles this is generally the name of the uploader, but if they have a user page listing a real name, that should be used.
Wikinews has loads of what are called "Infoboxes", you can find many of them at WN:IB (see Category:Infoboxes for a more complete list, including country and state infoboxes) and a quick browse through the list there will allow you to see that you can guess at the names of many with a fair degree of accuracy.
The most common infoboxes are for a country, topic, or major issue that remains in the news for some time. For the example article above you might want to use {{Crime and law}} (click the link to see the template). Like images, these go in blank lines between paragraphs. For a short story you want to insert it at the top after the date, but long articles can look good if the first paragraph is full width and the infobox is alongside the second and subsequent paragraphs.
—President BeeblebroxThe two templates {{QuoteLeft}} and {{QuoteRight}} are another decoration that can highlight some aspect of the story you are telling.
When you use these templates always make sure the text you're quoting from the article is actually in the article! Don't lift a quote from a source that is otherwise unused and add it in one of these templates.
To get the example shown in this section you would use the following syntax:
The {{haveyoursay}} template gives a handy link to the Wikinews Comments page, but it is rather boring and pedestrian. This is where {{HYS question left}} and {{HYS question right}} come into play; you can prompt discussion by asking a mildly provocative question aimed at getting people's opinions on the subject of the story.
If you add one of these templates, be sure to remove {{haveyoursay}} from the article so there is only one link on the page to the comments page.  The two "HYS" templates are also smart enough to work out when comments have already been left.  A link "Add comment" will be shown when there are no comments; when comments have been added a second link to view existing comments is provided.
The code to put in the HYS question box is as follows:
If your article doesn't meet some of the project guidelines you may end up with a warning template on it. Do not let this be too discouraging; read whatever guideline is highlighted and check the article's talk page (the "collaboration" tab at the top of the screen). There is no conspiracy to kill your article as our contributors want to see as many well-written articles on the front page as possible.
The above should show that it is relatively simple to put together a basic Wikinews article. Do not editorialise, and try to remain neutral. Wikinews is not a blog and does not have an opinion on the news it reports on.
Lastly, remember you are writing for a truly international audience. Don't assume people will, from a title or place name, recognise which country a story is about; there are multiple Presidents, Prime Ministers, and place names can be confusingly ambiguous.
Wikinews:Article layout in a nutshell