Quoting Dr. Greg Norris:
All of us should have a copy of the LCA textbook from Olivier Jolliet and colleagues. It is a free e-book, but also arguably the best available current LCA textbook! The one I use for my Harvard class too.
Environmental Life Cycle Assessment
By Olivier Jolliet, Myriam Saade-Sbeih, Shanna Shaked, Alexandre Jolliet, Pierre Crettaz
Available for download or viewing online here.