Working with Wikis
A wiki, like Wikipedia, is just a tool for making it easy to create and update web documents. In exchange for relatively "plain" web pages we have the ability for anyone anywhere to easily publish content with just a web browser.
To edit a page, click the Edit link that appears on each page. This is in the form of a tab at the top of the page. A form will appear, containing the existing prose and markup commands. When you have finished making modifications, click the Save button.
If all you do to start is type your prose in paragraph form with blank lines between the paragraphs the content will look fine. You can "grow into" the wiki markup language slowly as you need to.
You can embed many different types of images in a wiki page although the format dictates how much flexibility/features you have. In general you will want to convert images to JPG or PNG if you want to take advantage of thumbnails, re-sizing, etc.
- This is an example of a an embedded image with a thumbnail and caption:
The canonical reference for embedding images in MediaWiki syntax is here.