Wildcard's setting is in constant flux (hence the name), but don't let that intimidate you.
The world's structure is mostly as it is today, and technology hasn't leapt forward so strongly that it's hard to grasp. In fact, you'll be fine pretending it is today for most part, though the world is set 43 years in the future.
Beyond the basics, this is an encyclopaedia of current player knowledge, but it is quite in-depth. You don't need to know more than a fraction of what you find here at most - unless there is something specific you're looking for, in which case this encyclopaedia is a good place to start. Wondering about the progress of space exploration? You'd find it here. Wondering about the political stances of country X? The encyclopaedia is your drug. You get the point.
You can log in to this wiki using the username and password you used to sign up to the site with.
Dokuwiki has a Sitemap that makes navigation through the various subjects quite easy, but if you want help in identifying some of the most important topics, here is a list:
(It will be expanded as more topics are added to the encyclopaedia.)
Stuff to do: Wanted pages, Stuff tagged incomplete.