As you might have guessed from the title, this is going to be a list of pages on Senseis Library that I think are actually useful and would actually recommend that somebody else read. It gets populated mainly on the basis of travelling through the library on random mode, and stopping because I actually like the content.
If you want to learn how to play, or to teach others how to play, then check out CaptureGoTeachingMethod quickly introducing Go using AtariGo. A more advanced page is HowToLieWithTewari which makes some interesting points about evaluating joseki. If you want to know how to use this wiki, try HowToUseWiki
There are very few opening pages which are actually up to date