Please see http://doc.tikiwiki.org and please help if you can. Here at Tikiwiki we eat our own DogFood, so when you notice something missing, and you are a registered user of this site, you can add it yourself. Adding/editing a page is as simple as double clicking where you want the addition (unless you changed your preferences). Otherwise, just click edit.
There is also a legacy 350 page fully illustrated documentation for Tiki 1.6 (PDF). Tiki offers hundreds of new features and options since then. However, it is still a good introduction.
If you need help and/or want to meet members of the community, visit our IRC chatroom: irc.freenode.net #tikiwiki New to IRC? It's a great time to learn. Please see our step by step instructions on how to connect to TikiWiki's IRC channel
If you are just setting up, please see the Installation Documents. Once you have installed Tiki, please proceed to the Tiki Administrator Settings. Links to flash movies of a few Administrator settings are present at TikiMovies page.