Using the geometry
package it is possible to switch your layout mid-document using the \newgeometry{<settings>}
macro. We first set up the initial layout of the title page (1in
on all four sides) when the package is loaded
\usepackage[showframe,paper=a4paper,margin=1in]{geometry}% http://ctan.org/pkg/geometry
and then change this after the title page using
\newgeometry{top=1in,bottom=1in,right=0.5in,left=1.5in}
Here is the complete MWE:
\documentclass{article}
\usepackage[showframe,paper=a4paper,margin=1in]{geometry}% http://ctan.org/pkg/geometry
\usepackage{lipsum}% http://ctan.org/pkg/lipsum
\begin{document}
\begin{titlepage}
\thispagestyle{empty}
\author{Somebody Important}
\title{Something just as important}
\maketitle
\lipsum[1-2]
\end{titlepage}
\newgeometry{top=1in,bottom=1in,right=0.5in,left=1.5in}
\section{First section} \lipsum[1-4]
\section{Second section} \lipsum[5-8]
\section{Third section} \lipsum[9-12]
\section{Last section} \lipsum[13-16]
\end{document}

lipsum
provides dummy text, while the showframe
option to geometry
merely frames the page to highlight the layout of the text block and other areas.