With regard to your first question: Use the floatrow package -- it centers the content of floats by default.
\documentclass{article}
\usepackage[draft]{graphicx}
\usepackage{floatrow}
\begin{document}
The first paragraph.
\begin{figure}
\includegraphics{a.jpg}
\caption[Long caption]{Caption}
\label{pic-a}
\end{figure}
And the second.
\end{document}
If you don't want to load floatrow for whatever reason, you may instead add the following to your preamble (thanks to egreg for the tip):
\makeatletter
\g@addto@macro\@floatboxreset\centering
\makeatother
EDIT: The figure in my example only was vertically centered because I had not added any dummy text. Example corrected.
The file you linked to is not well set up for using as an example here, but the following works. (Note: I did not have the fonts in used in the linked file; but I assume you do.)
Rather than post the whole thing, which is very verbose, I'll point you to where to add or subtract or move things.
[1] Add \usepackage{graphicx} to your preamble. (I put it just after xcolor.)
[2] Move the 'TITLE' section inside the first minipage, following the \vspace{0pt} line; note that the example is missing a closing brace. I would do something like:
\par{\centering{\sffamily\Huge John Smith}\\ % Your name
{\color{headings}Curriculum Vit\ae}\par
} % <--- ADDED !
[3] Following the second \vspace{0pt}, add the following lines (but you can use the fonts the file has if they are on your system):
\begin{flushright}
\includegraphics[width=4cm,height=5cm]{photo.jpg}
\end{flushright}
[4] Now the second minipage is too long: you need to remove some material from the example file. For instance, if you comment out the 'Communication Skills' seciton, you'll see everything fits on one page. That means you'll need to move things around between the left and right minipages until everything fits; you may need to pare down how verbose you are in various sections.
Best Answer
You could use
backgroundfor this: