All articles begin with a sentence or definition describing the topic. The topic should be written in bold, and should be at the very beginning of that sentence. In addition, that definition should also include the Pokemon game or games dealing with that subject. The sentence itself may not be that complicated, for example, "Gold is a main character from the Pokemon game series," is a perfectly fine opening sentence. It's a nice, short lead-in to a lot of information.
The next few sentences in the paragraph should give an overview of the topic. If you are writing a short article on something that does not have a lot of detail or complexity, then an introductory-style paragraph or paragraphs may be all you write. If you are planning on writing a longer article, however, you will want to keep your information in the introduction basic, as the details will fit better in the subsections of the article.
The main reason for this is to help people who have not come directly from the wiki itself; there are visitors looking for information who come from search engines or other links, and may not be aware of the focus of the wiki when they first arrive on the page. By including this information right at the beginning, they'll know where they are and can see right away if the article will be of use to them. As an example, someone looking for information on Cloud's role in Final Fantasy VII or information on types of clouds in the sky would probably not be interested in a Pokemon article.
Sometimes, you will have a topic that has a lot of information in it, and will therefore need a longer article for a subject. Articles on Worlds, for example, are always divided into several parts, or subsections, to make it easier to find information on the world's layout, the plot taking place there, or even just where the treasure chests are located. There are two guidelines you should use when deciding on creating subsections within an article:
1. Does the subsection make it easy to find information in the article? A person may be searching on certain information on a topic, such as the weapons used by certain characters, or what role they played in games they were in. Can they find that information easily in the article, or do they have to comb through the article to find the section they want?
2. Is the subsection appropriate for the article? Think carefully about a subsection, especially when it overlaps with another article. A subsection on Misty's relationship with Ash in Pokemon would be appropriate for his article; however, describing isty herself would make more sense in her own article. Keep the article as focused on the subject as possible. After all, if someone wants more information on something else mentioned in the article, all they should have to do is click on a link to reach that article.
To Trivia, or Not to Trivia?
Be very careful about creating or adding a trivia or miscellaneous section to an article. Trivia sections can quickly grow out of control and make it hard to find information since they end up covering a broad range of topics. If you want to add something to an article, look at the existing sections and see if there are any places that information might be better put to use.
Finally, don't forget to add categories to a new article! They're so easily missed because they sit at the bottom, but they are quite useful for navigating. Make sure you pick the appropriate category or categories for a subject, and make sure you spell the category correctly. Often, category names are in plural form since they hold information on several topics instead of one or two things.