Installing ChurchInfo is fairly easy and the instructions are located in the html/churchinfo/Documentation/Readme.txt file. If you follow these directions, the majority of the installation will be done correctly.
There are, however, a couple of things that you may need to do that are not covered in the installation instructions.
Be certain to set the ownership and permissions of the /var/lib/php/session directory correctly. The location of this directory may vary according to your distribution and the version of PHP you are using.
There is also a module that was missing from my PHP installation. I had to install the php-mbstring package before ChurchInfo would work properly.