To summarize my Landmark Forum experience I would like to quote Alan Watts who said following more then 30 years ago in his talk on spiritual authority:

“… We are all basically scams and if you haven’t found that – you are very unconscious. I know all sorts of people who are full of outward love, but of course it always turns up that they need money. And where it comes to money, the virtue flies out of a window.”

In my opinion this summarizes what is right and what is wrong about Landmark Forum approach. I strongly recommend considering following material before attending Landmark Forum:

http://www.rickross.com/groups/landmark.html

Much if not all material on the course is based on Alan Watts's interpretation of Zen. I would strongly recommend consider the original material which is much richer, tested by time, more consistent and extremely enlightening to say at least:

http://www.alanwatts.com/aw_story.html
http://www.alanwatts.com/mp3_sel.html

Alan Watts is surely one of the best teachers of the eastern philosophy for the western audience and people who were brought up in Judea Christian tradition. For more practical approach on how to improve your life I would consider instead (of Landmark Forum) Personal Power by Anthony Robbins:
http://www.personalpower.com/

or/and

Habits Of Highly Effective People
Stephen R. Covey
http://www.amazon.com/exec/obidos/tg/detail/-/0671315285/ref=ed_oe_a/102-523321-8820947?v=glance&s=books&st=*