This is what places of business put in their window or other prominent location, usually in the form of a sign, banner, or other such thing when they are seeking new employees.
Sometimes seen in newspaper advertisements as well.
These words pop up everywhere after school lets out for the summer. (sometimes in the form of Help Wanted, Positions Available, or other similar terms).
For many, this presents an opportunity to get a summer job and make some money - whether to save for school, material possessions, or simply the future. This is perfectly fine and is what the majority of us students seem to do.
For others, however, these two simple words are most unwelcome because we simply wish to chill out and enjoy the warm weather and short freedom from school.
It's not that we're all a bunch of lazy slackers, druggies, or whatever - some of us are have a great work ethic and aspirations for the future - we just want to have a leisurely summer break (after working our a**es off all year in high school or college).
When parents, family, or other older adults see this sign, they nag us incessantly to sacrifice our well-deserved vacation and apply for a job.
Dad: Hey son, I saw a Now Hiring sign at the local grocery store. You need to go get a job.