[CentOS] A silly question about getting access to webapp installed with yum

Greetings,

I have helped host a few applications such as GLPI, OCSInventory, etc etc. using the tarball method and untarring them in /var/www/htom directory.

I have never done them though using yum.

I was trying to install Trac, Bugzilla etc using yum install method on a Centos 6.2 box.

Somehow I am not able to see the respective pages say even using http://localhost/trac or http://localhost/bugzilla

Now comes the elementary and stupid question:

Now where do these stuff get installed? they are not under /var/www/html

I did find some under /usr/share

Any pointers to instantiate them?

I am not good at understanding what that beast of yum does as to post install script. Though I have created a mysql with CSV and blackhole engines about a year back and as I did it for a client of the company where I worked then and cannot have my grubby hands on that script.

Any help appreciated.

TIA