The package nopageno will suppress page numbers in a whole document.
To suppress page numbers from a single page, use
\thispagestyle{empty} somewhere within the text of the
page. (Note that \maketitle and \chapter both use
\thispagestyle internally, so you need to call it after you've called
them.)
To suppress page numbers from a sequence of pages, you may use
\pagestyle{empty} at the start of the sequence, and restore
the original page style at the end.
Unfortunately, you still have to use \thispagestyle after any
\maketitle or \chapter command.
An alternative is to use the rather delightful
\pagenumbering{gobble}; this has the simple effect that any
attempt to print a page number produces nothing, so there's no issue
about preventing any part of LaTeX from printing the number.
However, the
\pagenumbering command does have the side effect that it resets the page
number (to 1), which may be undesirable.
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=nopageno