First off, to start editing and creating pages, you must create an account. There will be a CAPTCHA to keep away automated spammers, and you will have to open up the link in the verification e-mail sent to your e-mail address to confirm your account.
Editing is simple enough. Open up any existing pages in the Utaite and Songs categories, and click the Edit button to get started. Creating pages is a bit more difficult, and there are generally two ways to go about it:
1)Think of the title of the page that you want to create, and use this URL:
http://www.musicspeed.com/wiki/ARTICLE
Replace ARTICLE with whatever title your page is going to have. Please put _ where spaces would be if the title is more than one word. If your page is going to be about an album, then tag on a _(album) at the end of the title. Then click on Create page.
ex.A page about the song Sweet Devil would get the URL http://www.musicspeed.com/wiki/Sweet_Devil
ex2.A page about clear's album Dearest would get the URL http://www.musicspeed.com/wiki/Dearest_(album)
One thing I've noticed is that sometimes the wiki logs you out if you open up a wikiURL that doesn't exist yet.. I'm not sure why it does this, but just log back in and click Create to make the page.
2)Think of the title of the page that you want to create, and search for it in the Search box. Probably not a good idea to do this for albums. Then click on Create the page "title that you just searched for" on this wiki!
For pages about utaite(nico singers), include this on the bottom of the page:
[[Category:Utaite]]
For pages about songs, include this on the bottom:
[[Category:Songs]]
For pages about albums, the secret category that's not on the sidebar, include this on bottom:
[[Category:Albums]]
Not really going to be strict about this... just write whatever you feel is relevant! For pages on nico singers, generally try to include links to at least their MyList, Nico community, and blog if applicable. Try to include information on the singer's style, popularity, and most popular songs. On pages that I have made myself, I included links to every single one of an utaite's songs, along with Youtube mirrors, but this isn't necessary to do on every page. Links to a singer's most notable songs should suffice~
For pages on songs, try to include a link to the original PV on nico, a screenshot from the PV, the song producer, artist, and what vocaloid it was made for if applicable. There should also be a general description of what the song is about and it's impact(if any). As for including lyrics, those are kind of a touchy subject, since I know some people put a lot of work into transcribing lyrics and don't want people to take them without permission. If you are sure that the person who transcribed the lyrics won't mind them being on another site, then go ahead and include them. Be sure to include the sources in a reference section on the bottom of the page.
Image uploading is enabled, so go ahead and upload any pictures that would be useful to include in any pages. When embedding an image into a page, make sure to use a thumbnail(like 200px or 300px).
For more help concerning wiki code, the Help section on Mediawiki is very useful.