Added information about «showframe» package

lbol.tex

@@ -775,6 +775,16 @@ You can add options in the usual way:
 }
 \end{verbatim}
 
+\section{The \texttt{showframe} Package}
+
+If you are having difficulty figuring out your page layout, it can be helpful to see what you are actually adjusting. To do that, include the \texttt{showframe} and change the frame color to red by adding this to your preamble:
+
+\begin{Verbatim}[frame=lines, framesep=3mm, breaklines=true, label=\fbox{showframe package}]
+\usepackage{showframe}
+\renewcommand*\ShowFrameColor{\color{red}}
+\end{Verbatim}
+
+
 \section{Customizing Pages}
 
 If you need more granular control over your headers and footers, use the \texttt{fancyheader} package to get access to a lot of options. It will give you the ability to specify different content on even and odd header and footers, or on right and left headers and footers if your document is a \texttt{twoside} document.