Use the * version of the chapter and section commands, like this:

% a sample chapter
\chapter*{Latex FAQs}

% a sample section
\section*{Latex FAQs}

Note that the "normal" way of doing a chapter or section, which would include the correspond chapter or section number, is like this:

% a sample chapter
\chapter{Latex FAQs}

% a sample section
\section{Latex FAQs}