You should have a vanilla install of Ubuntu 32- or 64-bit up and running. Run updates before proceeding (System > Administration > Update Manager).
Do not install XAMPP, LAMPP, Apache, MySQL, etc. I thought I was going to be smart and bypass a bunch of installation steps by doing this, but it's just not necessary. If you do have LAMPP on your system and you still plan to use it, you better go read some docs on how to get it to start on another port, because the ZM installation is going to overtake all the default ports. If you have LAMPP and anything is running, stop all the services now with
sudo /opt/lampp/lampp stop
If you have existing Apache or MySQL running, you're on your own. This guide is meant for installing ZM on a dedicated box. Feel free to leave suggestions to include information on how to integrate zoneminder with a functioning Apache/PHP/MySQL setup.