Good question, It worked flawlessly for me. What distribution are you running?

I take it you did teh following in order first

sudo apt-get remove openoffice*.*
sudo add-apt-repository ppa:libreoffice/ppa
sudo apt-get update
sudo apt-get install libreoffice

Which means you should be able to open Synaptics and search for LibreOffice.

I'd suggest doing that and selecting LibreOffice for reinstall, and the LibreOffice-gnome for install.

try that and lets see what happens. as for running libreoffice, you should be able to run it from the CLI by typing libreoffice, if it installed correctly it should run.