I wouldn't say that I'm a vegetarian, but I understand why people choose that lifestyle out of respect for sentient life.
Are there personal benefits why a person would become a vegetarian?
Because it is the absence of eating meat and so the abstentation of by products from slaughter, there are a few animal based problems you'd avoid. 
How can one become a better vegetarian?
Better vegetarian is tough to answer, but there are steps up from vegetarianism.  There's veganism, and they exclude all animal by products in addition to every vegetarian.  So no eggs or dairy.