Page numbering at top of page

You can load the scrpage2-package from the koma-script-bundle. \maketitle has hard coded a \thispagestyle{plain}, Which gives you page number centred at bottom. To get rid of the page number at page one, place \thispagestyle{empty} after the \maketitle-command.

scrpage2 is documented at page 196 in the English manual (chapter 5).

And MWE:

\documentclass[10pt]{article}
\usepackage{array, xcolor, lipsum, bibentry}
\usepackage[margin=3cm]{geometry}
\usepackage{scrbase,scrpage2}
\pagestyle{scrheadings} % pagestyle with page number

\title{\bfseries\Huge John Doe}
\author{}
\date{}

\definecolor{lightgray}{gray}{0.8}
\newcolumntype{L}{>{\raggedleft}p{0.14\textwidth}}
\newcolumntype{R}{p{0.8\textwidth}}
\newcommand\VRule{\color{lightgray}\vrule width 0.5pt}


\begin{document}
\maketitle
\thispagestyle{empty} % place this after \maketitle
\vspace{1em}
\begin{minipage}[ht]{0.48\textwidth}
Address Line 1\\
Address Line 2\\
Address Line 3\\
Address Line 4\\
Address Line 5
\end{minipage}
\begin{minipage}[ht]{0.48\textwidth}
Mobile: 123-456789\\
Email: [email protected]\\
Date of Birth: 01/01/2012\\
Citizenship: My citizenship
\end{minipage}
\vspace{20pt}

\section*{Education}
\begin{tabular}{L!{\VRule}R}
2008--2012&MSc in Computer Science, Great University, Country.\vspace{5pt}\\
2006--2008&BSc in Life Science, Great University, Country.\\
\end{tabular}

\section*{Employment}
\begin{tabular}{L!{\VRule}R}
2011--today&{\bf Company Name.} Head of Department. Add my job description here. Add my job description here. Add my job description here. Add my job description here.\\
&\begin{itemize}
\item Add my job description here.
\item Add my job description here.Add my job description here.Add my job description here.
\item Add my job description here.Add my job description here.Add my job description here.Add my job description here.
\item Add my job description here.Add my job description here.Add my job description here.Add my job description here.Add my job description here.Add my job description here.Add my job description here.Add my job description here.Add my job description here.
\end{itemize} 
\end{tabular}

\section*{Awards and Achievements}
\begin{tabular}{L!{\VRule}R}
2008&Gold medal.\vspace{5pt}\\
2006&Silver medal.\\
\end{tabular}

\section*{Organisational Experience}
\begin{tabular}{L!{\VRule}R}
2008&This event.\vspace{5pt}\\
\end{tabular}

\newpage

\section*{Languages}
English, Spanish, French, German


\end{document} 

have a look at the fancyhdr package. there you can define your headings as you want.

try this:

\documentclass[a4paper,10pt]{article}

\usepackage{blindtext}
\usepackage{fancyhdr}

\pagestyle{fancy}
\lhead{john doe}
\chead{}
\rhead{\thepage} % set the page number to the haed line
%clean the foot line
\lfoot{}
\cfoot{}
\rfoot{}

\begin{document}
\blindtext
\newpage
\blindtext
\newpage
\end{document}