If you are new to the wiki culture, here are few of the page elements, and features you may learn to enjoy, and the many features that this wiki engine PmWiki offers:

editable pages
Really! The best thing about wikis is that you can edit the pages you read if you find something incorrect or just incomplete in them. Just click the "Edit Page" links, at the top and/or bottom of any page, to edit that page.
track changes
If you'd like to know who wrote what, or how a page evolved, click the Page History links (top and/or bottom of any page).
find new changes
It is possible to check what pages have changed since you last visited a wiki; if you know when you visited last, click the Recent Changes links (top/bottom of page) and check out the recent page history of the pages modified since your visit. That shows the latest files in the current page group; for a list of changes to the whole wiki, there's a special page: Site.All Recent Changes. Also RecentUploads? and Site.AllRecentUploads?.

(note: it would be nice to be able to aggregate changes since a specific date - on a Site.ChangesSince page, maybe?)

integrated search
Besides searching a wiki, one can also make use of the integrated search, which, in wikis such as PmWiki, can make use of the underlying structure of the wiki in order to leave out pages that (in the opinion of the wiki administrator) are known to be irrelevant. (maybe a link to a page on search techniques here?)
PmWiki is one of the wikis that allows readers and authors to change the look and feel of the pages with one mouse click; the content stays the same, but it is displayed in many different ways, adding decoration and even different functionality. You could click on a few skin links on this page to get a glimpse of it.
Are automatic guided tours, like the one you are on right now. See the links at the end of this list, the ones surrounded by << and >> ? the link in the middle is the trail's table of contents; it determines the order in which you can go through these pages. The left link takes you 'back' (or up on the TOC list: it's blank now because this is the first page on the documentation trail), while the right link takes you forward (or down on the TOC). Just as you'd expect from a well-behaved book. :)
page categories
Another way we can associate pages in PmWiki is by category. To find a list of categories used on this particular wiki you're using at the moment, see Category.Category?.
page hierarchy
Normally wikis are totally flat; that is, all pages appear to be located in the same 'directory'; PmWiki uses Wiki Groups to simulate an extra level, and to add more precise content (and security policy) separation; it is also possible to simulate an arbitrarily deep hierarchy by nesting PmWiki fields
Wikis are supposed to be totally open, and in an ideal world they would be; however, because of people who get a kick out of defacing wikis, some security can be added. PmWiki offers a flexible security model, in which a wiki, a group or even an individual page can be password-protected for administration, editing and even reading. So if you are prompted for a password, and you know it, just fill it in :)

This page may have a more recent version on PmWiki:WikiElements, and a talk page: PmWiki:WikiElements-Talk.