Nosocomial. Nosocomial means hospital acquired. The most important precaution is to use frequent hand washing anytime a patient is seen and between patients. For some types of infections, such as MRSA a private room with gowns and gloves and other protective gear may be needed.
Universal protection. Hand washing in between patients, use of proper protective gears.
Yes. Hand wash and direct contact.
Sadly probably not. We are exposed to staph frequently (other people, household objects, even pets) so it is very difficult to avoid it completely. If the opportunity arises, the staph on our body can cause infection. But, good hand hygiene (washing frequently and using hand sanitizers), avoiding touching our faces/noses, and being careful with personal items (combs, towels, etc) probably help.