Page styles
The style of a page determines where LaTeX places the components of that page, such as headers and footers, and the text body. This includes pages in the main part of the document but also includes special pages such as the title page of a book, a page from an index, or the first page of an article.
The package fancyhdr is very helpful for constructing page styles. See its documentation on CTAN.

\maketitle
Synopsis:

\maketitle

Generate a title. In the standard classes the title appears on a separate page, except in the article class where it is at the top of the first page. (See Document class options, for information about the titlepage document class option.)
This example shows \maketitle appearing in its usual place, immediately after \begin{document}.

\documentclass{article}
\title{Constructing a Nuclear Reactor Using Only Coconuts}
\author{Jonas Grumby\thanks{%
    With the support of a Ginger Grant from the Roy Hinkley Society.} \\
  Skipper, \textit{Minnow}
  \and
  Willy Gilligan\thanks{%
    Thanks to the Mary Ann Summers foundation
    and to Thurston and Lovey Howell.}           \\
  Mate, \textit{Minnow}
  }
\date{1964-Sep-26}
\begin{document}
\maketitle
Just sit right back and you'll hear a tale, a tale of a fateful trip.
That started from this tropic port, aboard this tiny ship. The mate was
a mighty sailin' man, the Skipper brave and sure. Five passengers set
sail that day for a three hour tour. A three hour tour.
  ...

You tell LaTeX the information used to produce the title by making the following declarations. These must come before the \maketitle, either in the preamble or in the document body.
\author{name1 \and name2 \and ...} 	 Required. Declare the document author or authors. The argument is a list of authors separated by \and commands. To separate lines within a single author’s entry, for instance to give the author’s institution or address, use a double backslash, \\. If you omit the \author declaration then you get ‘LaTeX Warning: No \author given’.
\date{text} 	 Optional. Declare text to be the document’s date. The text doesn’t need to be in a date format; it can be any text at all. If you omit \date then LaTeX uses the current date (see \today). To have no date, instead use \date{}.
\thanks{text} 	 Optional. Produce a footnote. You can use it in the author information for acknowledgements as illustrated above, but you can also use it in the title, or any place a footnote makes sense. It can be any text at all so you can use it for any purpose, such as to print an email address.
\title{text} 	 Required. Declare text to be the title of the document. Get line breaks inside text with a double backslash, \\. If you omit the \title declaration then you get ‘LaTeX Error: No \title given’.
To make your own title page, see titlepage. You can either create this as a one-off or you can include it as part of a renewed \maketitle command. (Many publishers will provide a class to use in place of article that formats the title according to their house requirements.)

\pagenumbering
Synopsis:

\pagenumbering{number-style}

Specifies the style of page numbers, and resets the page number. The numbering style is reflected on the page, and also in the table of contents and other page references. This declaration has global scope so its effect is not delimited by braces or environments.
In this example, before the Main section the pages are numbered ‘a’, etc. Starting on the page containing that section, the pages are numbered ‘1’, etc.

\begin{document}\pagenumbering{alph}
  ...
\section{Main}\pagenumbering{arabic}
  ...

The argument number-style is one of the following (see also \alph \Alph \arabic \roman \Roman \fnsymbol).
arabic 	Arabic numerals: 1, 2, …
roman 	lowercase Roman numerals: i, ii, …
Roman 	uppercase Roman numerals: I, II, …
alph 	lowercase letters: a, b, … If you have more than 26 pages then you get ‘LaTeX Error: Counter too large’.
Alph 	uppercase letters: A, B, … If you have more than 26 pages then you get ‘LaTeX Error: Counter too large’.
gobble 	 LaTeX does not output a page number, although it does get reset. References to that page also are blank. (This does not work with the popular package hyperref so to have the page number not appear you may want to instead use \pagestyle{empty} or \thispagestyle{empty}.)
Traditionally, if a document has front matter—preface, table of contents, etc.—then it is numbered with lowercase Roman numerals. The main matter of a document uses arabic. See \frontmatter & \mainmatter & \backmatter.
If you want to change where the page number appears on the page, see \pagestyle. If you want to change the value of the page number, then you manipulate the page counter (see Counters).

\pagestyle
Synopsis:

\pagestyle{style}

Declaration that specifies how the page headers and footers are typeset, from the current page onwards.
A discussion with an example is below. Note first that the package fancyhdr is now the standard way to manipulate headers and footers. New documents that need to do anything other than one of the standard options below should use this package. See its documentation on CTAN.
Values for style:
plain 	The header is empty. The footer contains only a page number, centered.
empty 	The header and footer are both empty.
headings 	Put running headers and footers on each page. The document style specifies what goes in there; see the discussion below.
myheadings 	Custom headers, specified via the \markboth or the \markright commands.
Some discussion of the motivation for LaTeX’s mechanism will help you work with the options headings or myheadings. The document source below produces an article, two-sided, with the pagestyle headings. On this document’s left hand pages, LaTeX wants (in addition to the page number) the title of the current section. On its right hand pages LaTeX wants the title of the current subsection. When it makes up a page, LaTeX gets this information from the commands \leftmark and \rightmark. So it is up to \section and \subsection to store that information there.

\documentclass[twoside]{article}
\pagestyle{headings}
\begin{document}
  ... \section{Section 1} ... \subsection{Subsection 1.1} ...
\section{Section 2}
  ...
\subsection{Subsection 2.1}
  ...
\subsection{Subsection 2.2}
  ...

Suppose that the second section falls on a left page. Although when the page starts it is in the first section, LaTeX will put ‘Section 2’ in the left page header. As to the right header, if no subsection starts before the end of the right page then LaTeX blanks the right hand header. If a subsection does appear before the right page finishes then there are two cases. If at least one subsection starts on the right hand page then LaTeX will put in the right header the title of the first subsection starting on that right page. If at least one of 2.1, 2.2, …, starts on the left page but none starts on the right then LaTeX puts in the right hand header the title of the last subsection to start, that is, the one in effect during the right hand page.
To accomplish this, in a two-sided article, LaTeX has \section issue a command \markboth, setting \leftmark to ‘Section 2’ and setting \rightmark to blank. And, LaTeX has \subsection issue a command \markright, setting \rightmark to ‘Subsection 2.1’, etc.
Here are the descriptions of \markboth and \markright:
\markboth{left-head}{right-head} 	Sets both the right hand and left hand heading information for either a page style of headings or myheadings. A left hand page heading left-head is generated by the last \markboth command before the end of the page. A right hand page heading right-head is generated by the first \markboth or \markright that comes on the page if there is one, otherwise by the last one that came before that page.
\markright{right} 	Sets the right hand page heading, leaving the left unchanged.

\thispagestyle
Synopsis:

\thispagestyle{style}

Works in the same way as the \pagestyle (see \pagestyle), except that it changes to style for the current page only. This declaration has global scope, so its effect is not delimited by braces or environments.
Often the first page of a chapter or section has a different style. For example, this LaTeX book document has the first page of the first chapter in plain style, as is the default (see Page styles).

\documentclass{book}
\pagestyle{headings}
\begin{document}
\chapter{First chapter}
  ...
\chapter{Second chapter}\thispagestyle{empty}
  ...

The plain style has a page number on it, centered in the footer. To make the page entirely empty, the command \thispagestyle{empty} immediately follows the second \chapter.