include accent, comments in latex file

1) for including accents in latex file:

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern} 

Then we can type the characters directly into your source file.

2) for including the comments at the side of document, a good tool is todonotes.

\usepackage{todonotes}

\begin{document}

Here is the document.  

\todo[color=green!40] {Here are some comments}.

\end{document}