1) Log in using the link in the upper right.
(Note: Unfortunately, to keep spammers at bay we are not allowing public registration. Please ask, in email or in person, about a wiki editing account. This is not the same as a user for the tokyohackerspace.org site. We apologize for the inconvenience.)
2) Navigate to the page you want to change and hit the “edit” tab above the text part of the page.
Note: Editing a page that already exists is fairly straightforward, but creating a new page out of nothing can be a little unintuitive at first. To create a completely new page, first make a link to the page you want to create somewhere else on the site using double brackets (e.g. make a specific meeting on the meeting notes page). It should appear red, indicating that no page by that name exists yet. Then click that link - if you're logged in, the wiki should prompt you to make a new page at that location. Voila! (In other words…link to new content then create the new content, as opposed to create new content then link to new content.)
3) Write some stuff.
Note: You don't need to know wikicode (the formatting markup, almost like a quick and dirty html) to write something - text and line breaks are sufficient to get many points across.
If you want to make it look a bit snazzier, here are some formatting guides:
4) Hit “Save Page” at the bottom to publish changes.
Note: The preview button next to “Save Page” is very useful for seeing how your page will look before you officially publish it.