The wiki doesn't exactly have a style guide, (see the draft proposal for a Style guide here: OLPC:Style guide. But there are some basic elements and tips that are generally true for any wiki.
Here are some hints for how to do wiki markup, the language behind the 'Edit' button on each page of the wiki:
 Editing Hints
Here are some common glitches you can look for when editing:
- Using http links to wiki pages: http://wiki.laptop.org/go/Wiki_cleanup should be [[Wiki cleanup]].
- Not using user-friendly wiki links: [[Wiki_cleanup]] should be [[Wiki cleanup]].
- Some unfriendly links provide alternate text that's not needed once they're made user-friendly: [[Wiki_cleanup|Wiki cleanup]] should be [[Wiki cleanup]].
- Pages with excessive <br> tags or <pre> that can be replaced with whitespace.
- Page Titles and Section Headings With Excessive Capitalization: normally just capitalize the first word (but first check "What links here" and/or set up a #REDIRECT).