You are probably here because you would like to contribute to the Wiki but don't know where to start. First of all, let me just say, "Thanks!"
Ok, down to business.
Create an account
The first thing you're going to want to do is create an account. An account is required to edit any pages. Click the following link (unless you're a spambot): Create an account
Asking for help
If at any time you have questions, you can ask them by going to the talk page of one of our fine admins: Kabutton or Spookypeanut. You can ask a question by clicking the edit link (top of the page, right side) and editing it like you would any other page on the wiki. Sign your name to your question (so we know who's asking) by clicking the signature button:
Creating a page
You can create a page by clicking on any red link (see below)
This will take you to a blank canvas where you can type in whatever you like. Changes are not permanent (and viewable by others) until the page is saved. Alternatively, if you search for a page, and that page does not yet exist, you will be taken to a search results page where there are links to pre-existing pages that might be similar to your search, as well as a red link to create that page (see below)
A list of the most wanted pages (by number of times they're linked to) is available at Special:Wantedpages.
Read the page of Etiquette and Protocol to get ideas about how to quickly create episode and guest pages, which are the main types of pages on the wiki.
We love to categorize our pages. In particular, guests and episodes go into specific categories for the purposes of organization and sorting. To put something in a category, use this code anywhere on the page (usually at the end):
[[Category:Whatever the category name is]]
For a list of possible guest categories, see Help:Guest Categories. For a list of episode categories, see Help:Episode Categories. Because there are many ways to refer to the films, Help:Film names is a page that lists how each movie is referred to on the wiki (for the sake of consistency). A complete list of categories is available at Special:Categories.