\documentclass{minimal}
\usepackage{arabxetex} % default option is "novoc"
                      % other options are "voc", "fullvoc", "utf" and "trans"
% arabxetex loads bidi.sty and fontspec.sty

\newfontfamily\arabicfont[Script=Arabic]{Amiri}
% you can also define \farsifont, \uighurfont, etc if you want
\begin{document}
This is some text in English with Arabic insertion \textarab{`arabI}.

This is some text in English with Arabic insertion \textarab[utf]{عربي}.

This is some text in English with Arabic insertion \textarab[voc]{`arabI}.

\begin{arab}
wa-ha_dihi fiqraT"uN bi-al-`arabiyaT ma`a kalimaT inklIziyaT (\textLR{English}).
\end{arab}

\begin{arab}[utf]
وهذه فقرةٌ بالعربية مع كلمة انكليزية (\textLR{English}).
\end{arab}

\begin{arab}[novoc]
وَهَذِهِ فِقرَةٌ بِالعَرَبِيَة مَعَ كَلِمَة اِنكلِيزِيَة (\textLR{English}).
\end{arab}
\end{document}