Add a quote to a blank page centered

The style chosen will depend heavily on the style you're using for other elements of your document (for example fonts, page layout, sectional units formatting), so it's difficult to produce a "universal solution". Here's one possibility; I chose not to center it vertically but to use the double of space below the quote than the space above it; the width of the \parbox is calculated as the width of the longest line of the quote (stored in the length \longest):

\documentclass{article}
\usepackage{lmodern}

\newlength\longest

\begin{document}

\clearpage

\thispagestyle{empty}
\null\vfill

\settowidth\longest{\huge\itshape just as his inclination leads him;}
\centering
\parbox{\longest}{%
  \raggedright{\huge\itshape%
   A man ought to read \\ 
  just as his inclination leads him; \\
  for what he reads as a task \\ 
  will do him little good.\par\bigskip
  }   
  \raggedleft\Large\MakeUppercase{Samuel Johnson}\par%
}

\vfill\vfill

\clearpage

\end{document}

babrbara beeton suggested to place the author flush right as it's often used in epigraphs:

\documentclass{article}
\usepackage{lmodern}

\newlength\longest

\begin{document}

\clearpage

\thispagestyle{empty}
\null\vfill

\settowidth\longest{\huge\itshape just as his inclination leads him;}
\centering
\parbox{\longest}{%
  \raggedright{\huge\itshape%
   A man ought to read \\ 
  just as his inclination leads him; \\
  for what he reads as a task \\ 
  will do him little good.\par\bigskip
  }   
  \raggedleft\Large\MakeUppercase{Samuel Johnson}\par%
}

\vfill\vfill

\clearpage

\end{document}

This should get you started:

\documentclass{article}
\usepackage{lipsum,csquotes,setspace}
\usepackage[charter]{mathdesign}
\usepackage[a4paper,margin=1in,showframe]{geometry} %%remove showframe in your document
%
\makeatletter
\def\nobottom{%
\def\@texttop{\ifnum\c@page>0\vskip \z@ plus 3fil\relax\fi}
\def\@textbottom{\ifnum\c@page>0\vskip \z@ plus 2fil\relax\fi}}
%
\def\resetopandbottom{%
\def\@texttop{\ifnum\c@page>0\vskip 0pt plus .00006fil\relax\fi}
\def\@textbottom{\ifnum\c@page>0\vskip 0pt plus .00006fil\relax\fi}}
\makeatother
%
\begin{document}
\nobottom
\pagestyle{empty}
\begin{displayquote}[\upshape\bfseries Author 1955][---]
\onehalfspacing\Large\itshape
\lipsum[1]
\end{displayquote}
\clearpage
%
\resetopandbottom
\pagestyle{headings}
%
\lipsum[1-10]
%
\end{document}