There are two types of talk pages — standard talk pages are used to discuss an article, a template, a category, etc., while user talk pages are used to communicate with other users or leave them messages. Every page has an associated talk page, except pages in the Special: namespace. If there has never been any text on a talk page, the link to the talk page from the article, category, etc., will be red. You can still discuss the page - you will just be the first person to edit the respective talk page.
Article talk pages are provided for discussion of the content of articles and the views of reliable published sources. They should not be used by editors as platforms for their personal views.
Accessing a talk page
To access a talk page look for a link labeled Talk, Discussion or Discuss this page. These links will be found either at the top of the page or on the left hand side (near Edit this page).
The name of a talk page is "Talk" plus the main page's title. If the main page has a prefix then talk is added after this prefix. For example, a talk page associated with the user namespace has the prefix User talk:; the main talk page for a user is User talk:ExampleUser. This article is in the Help: namespace, so the talk page for this article is Help:Talk page. The Main Page is in the main namespace (because it has no prefix), so its talk page is simply Talk:Main Page.
After someone else edits your user talk page, the alert "You have new messages" is automatically displayed on all pages you view, until you view your user page.
Using talk pages
You should sign and date your contributions on all talk pages by typing four tildes: (~~~~), which will yield something like: Username 19:36, 10 January 2006 (UTC).
On a talk page, "this page" usually refers to the article page (i.e. the page the talk page is associated with). If the talk page itself is referred to, write "this talk page".
When debating the name of the page or discussing merging it with another page, always mention the current page name. Otherwise after renaming (moving) a page, references to "this page name" become ambiguous.
The "Post a comment" feature (the small "+" sign on a separate tab, at the top of a talk page) allows you to start a new section without needing to edit the whole page. The section header becomes the edit summary at the time you save the page, so there is no edit summary displayed when you use this feature.
The practice of posting similar messages to more than a few users' talk pages, for example to solicit a certain action - is strongly discouraged.
Because the wiki software platform provides for a wide range of formatting styles, proper or at least consistent formatting is essential to maintaining readable talk pages.
The reference of a comment is determined by the number of colons (':') in front of it. If a reply is made to a statement, you should add a colon to the number of colons used in the statement being replied to. This style of conversation is easy to read.
How's the soup? --[[John]]
The above will produce this:
How's the soup? --John