What are the benefits you get ? How do you chant ? Thanks !

Correct spelling is amituofo

I didn't want to sound like a broken record here, but Google is a wonderful tool. If you Google the name you will find out how to chant for this. ;)

There are differences depending on the exact sect of Pure Land
Buddhism involved, but the main idea for the chanting is to have Amitabha Buddha take your soul to the Pure Land when you die. The Pure Land is a place in which you are not yet enlightened, but also not stuck being reborn. In the Pure Land everything leads to enlightenment, so you're pretty much guaranteed to make it once you enter. Others see this as a metaphor for life and not dead and how we can attain enlightenment while living through these efforts. Hope that helps, I'm by no means an expert but I do know a little about these things.