First of all, you can encolose the title page in a titlepage environment so the document class deals with it in a proper way.
Then you can set the distances between text blocks in a relative way to each other (by using the \stretch command), so if you are required to change the paper size (university policies with respect to thesis formatting can be very annoying) they still keep the same proportion on the page.
You can also define picture sizes relative to document parameters, by defining lengths as a number multiplying predefined constants, say defining width as a multiple of \textwidth. Be sure to use a vectorial picture so it does not suffer loss of quality due to resizing (and also makes for smaller file sizes). You can find the UNICAMP logo in several formats here (Beware: the eps version has some gibberish code written after the postscript code. Get rid of it otherwise LaTeX won't like it).
You can fine-tune the margins further by using commands from the geometry package.
So a full example of a titlepage would be
\usepackage{graphicx}
\usepackage[a4paper]{geometry}
...
\begin{titlepage}
\includegraphics[width=.1\textwidth]{your-university-logo}
\centering
\vspace{\stretch{1}}
\Large{Your Name}
\vspace{\stretch{1}}
\LARGE{\textbf{Your Thesis Title}}
\vspace{\stretch{2}}
\Large{Your City\\Date}
\end{titlepage}

:)I tried to find out the reference to this cover page format in the Unicamp guidelines, but the layout I found is slightly different. Do you have a link to this specific part? – Paulo Cereda Oct 24 '13 at 13:53abntex2bundle, you should redefine the\imprimircapamacro. – henrique Oct 24 '13 at 15:17