\documentclass{article}
\title{How I spent last summer}
\author{Your name\\
School of Mathematics and Physics,\\
University of Lincoln}
\date{October 31, 2016}
\begin{document}
\maketitle
\begin{abstract}
In this article, I shall discuss how I spent last summer
\end{abstract}
\section*{Introduction}
Note: no number for this section's title. The beginning is described in Section 1, summer proper in Section 2.
\section{Summer begins}
Summer begins in May?
\subsection{May weather}
It was raining \textit{a lot}. This phenomenon is explained in \cite{Section 4}{weather}.
\subsection{May activitites}
Because of what is described in Subsection 1.1, we stayed indoors and read the book \cite{book}. (Use labels in bibitems! not simply numbers.)
\section{Summer proper}
Whatever.
\begin{thebibliography}{9}
\bibitem{book}
S. Someone, \textit{A great book}, Lincoln, 2014.
\bibitem{weather}
A. Nother, Recent advances in weather prediction, \textit{J. Adv. Weather} \textbf{76}, no. 3 (2013), 23-45.
\end{thebibliography}
\end{document}