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?
aesthetic, economic, or personal preference. There are variations of the diet as well: an ovo-lacto vegetarian diet includes both eggs and dairy products, an ovo-vegetarian diet includes eggs but not dairy products, and a lacto-vegetarian diet includes dairy products but not eggs. A strict vegetarian diet – referred to as "vegan" – excludes all animal products, including eggs and dairy. Avoidance of animal products may require dietary supplements to prevent deficiencies such as vitamin B12 deficiency, which leads to pernicious anemia.
conscious of their behavior and have a choice; this is why there are laws governing human behavior, and why it is subject to moral standards.
Ethical vegetarian concerns have become more widespread in developed countries, particularly because of the spread of factory farming, more open and graphic documentation of what human meat-eating entails for the animal, and environmental consciousness. Some proponents of meat-eating argue that the current mass demand for meat has to be satisfied with a mass-production system, regardless of the welfare of animals