Edit: Due to the fact that this article is old, the installation instructions may not work anymore. In order to successfully install the latest version of PlayOnLinux, please access the playonlinux tag and open the latest article (the one on top).

The latest installation instructions for PlayOnLinux
Hello Linux Geeksters. As you may know, PlayOnLinux is a frontend for Wine, the popular software for running Windows applications on Linux and Mac OS X. The latest PlayOnLinux version available is PlayOnLinux 4.2.1, which has been recently released.
In this article I will show you how to install PlayOnLinux 4.2.1 on Ubuntu 13.10 Saucy Salamander, Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal, Ubuntu 12.04 Precise Pangolin, Linux Mint 16 Petra, Linux Mint 15 Olivia, Linux Mint 14 Nadia and Linux Mint 13 Maya.
PlayOnLinux 4.2.1 is availble in the default repositories for Ubuntu 13.10 Saucy Salamander and Linux Mint 16 Petra, so, all you have to do to install it is:
$ sudo apt-get update
$ sudo apt-get install playonlinux
To install PlayOnLinux 4.2.1 on Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal, Ubuntu 12.04 Precise Pangolin, Linux Mint 15 Olivia, Linux Mint 14 Nadia and Linux Mint 13 Maya, do:
$ wget -c www.playonlinux.com/script_files/PlayOnLinux/4.2.1/PlayOnLinux_4.2.1.deb
$ sudo apt-get install p7zip-full
$ sudo dpkg -i playonlinux.deb
Next, use the graphical interface instructions, for a successful installation.