Wiki quick start
 Before editing
The main idea a Wiki is anyone with knowledge can jump in on any page to create topics, links, add to information, ask questions, etc. Wikis, including this one, are typically completely public, the idea is to share information and constantly improve it. Other services, such as Google Docs, are more suitable for shared editing of private documents.
Wikis are very free form, their structure is developed organically in typical hypertext (1965) fashion. Thus rather than relying on a determined structure, you can link to pages, create menus, branch off into new sets of topics, etc as required.
It is very important to name your pages well. Make sure they are short, but distinctly identify your topic. A typical workflow is to mention something in a page in passing, then as it evolves it becomes its own section, finally it becomes its own page via a link, but if you know a topic is important you should create a new page for it immediately.
Before editing pages, it is recommend you create an account using the Log In / Create Account link in the upper right of every page. You should also authenticate your email (by following the instructions sent to you after creating your account). Your email address and other information is kept private by the software. You can still edit pages without creating an account, but you have to confirm each edit with a simple question (to prevent spam), and you won't be able to keep track of pages you've edited or subscribe to page changes.
This seems complicated, but in 5 minutes you should be creating basic pages!
 Editing pages
For experimenting with page editing, create and edit pages from the Sandbox. You may want to open that page in a new browser window now for reference.
You can edit any page by clicking the edit link on the top, or edit page sections when available (click "edit" on the right side of a subheading). This lets other people edit other sections of the page while you work (there is no way to reconcile two people submitting concurrent edits of a page).
An Editing help link will appear at the bottom of the editing form, use it to learn about wiki formatting. Wiki editing emphasizes meaning over formatting, and is designed to work from any Web browser. Linking (hypertext links) is a important part of wikis. You can create links (using the two square brackets - [[Wiki quick start]] would link to this page. Page links are blue when the linked page exists, red when it does not.
You can also "sign" text by adding four tildes - ~~~~, which will add your name and the edit date. This is typically used on discussion or news pages.
 Keeping track of changes
The simplest way to view changes is to use the Recent Changes link on the left. That page and individual pages also include links for Atom and RSS feeds if you use a syndication aggregator (highly recommended for keeping tack of changes across many sites). Recent browsers support easy access to syndication. A third way is to use the 'E-mail me when a page on my watchlist is changed' option on your Preferences page, then click the Watch link on individual pages.
 More information
Always try to find the most appropriate place to create your page, and link to it from anywhere appropriate. Since Wikis have very free from structures, occasional "Wiki gardening" is inevitable. Wiki gardening involves reformatting or editing text, removing redundant text, moving text to other pages, creating sections, and moving developed topics to their own page. Pages can be redirected to a new page using the Move link. This is done for the purpose of making text more clear or more easily reusable.
Don't worry too much about "ruining" pages, full histories are kept for every page, which can be organized or reverted as required.
The Discussion link should be used to organize information about a page, comment on changes, and so on. The Discussion link can be as important as the main topic page itself.
You can also create categories of pages, which can then be viewed in specific tables of contents. Semantic content is also supported, for queries, maps, calendars, etc.
Note you should not enter private information (while this wiki isn't "published," it is publicly available and will be found by search engines), nor violate copyright. It is also far better to store data in Wiki markup rather than attachments (Word, PDF, etc).