Seven signs of a bad company to work for
You shouldn't take a job without paying a visit to where you'll be working. Note the attitudes and interactions of the workers there as well as the overall environment, including employee common areas. Warning signs include unclean or unsafe-looking work spaces, angry-looking posters (such as "ALL EMPLOYEES MUST WEAR BADGES!") and disgruntled faces on employees.
If a visit to the office is depressing, you won't want to work there for several hours a day.