We learn a lot in school, but unfortunately, information about work relationships is usually not offered, much less required, reading. Once you get into the working world, you may run into people who are difficult or don’t play by the rules. Here are some tips you were probably never taught in school. 1. Do your due diligence before letting your guard down with colleagues. Avoid people who are manipulative or who color the truth to show themselves in a better light. Steer clear of those who play “let’s get what we can.” One bad relationship can ruin your entire career. Keep things light and po…