You need access to a computer with LaTeX on it. An online connection would be helpful regarding installation and updates. LaTeX can be installed on most operating systems, so you can use Windows, Linux, Mac OS X, or Unix.
This book uses the freely available TeX Live distribution, which runs on all mentioned platforms. You just need an online connection or the TeX Live DVD to install it. In the book, we work with the cross-platform editor TeXworks, but you could use any editor you like.