Where can I find the location of folders for installed programs?

Also, if you just need to know where the executable is you can run whereis executable or which executable For instance:

$ whereis firefox
firefox: /usr/bin/firefox /etc/firefox /usr/lib/firefox /usr/share/man/man1/firefox.1.gz

$ which firefox
/usr/bin/firefox

on the command line, you can use dpkg --listfiles packagename. For instance, dpkg --listfiles firefox. If you want to see what files a package contains without installing it, then you can install apt-file and use that.

But you really shouldn't mess with it. There is usually no reason to manually interfere with the contents of a package. All configuration files for normal applications are placed in the users home directory. You don't have savegames in C:\Programfiles\Appname\savegames, for instance. They would be placed in /home/username/.local/share/appname/savegames. That way, if you move your home directory to another machine, it keeps all configurations and user data.

http://packages.ubuntu.com/natty/i386/banshee/filelist

or

dpkg -L banshee