This is a phrase that is conceptually related to driving a vehicle. The phrase is essentially saying to avoid a certain person, place, or thing. This is similar to avoiding obstacles when using the steering wheel while driving a car.
The phrase can be used as a suggestion: “He recommends that people steer clear of the hot peppers at the salad bar.” In this phrase, the person is recommending that people not eat the hot peppers. It can also be used a personal statement in a conversation: “I am steering clear of restaurants like that.” This is simply saying that such restaurants are not being visited by the person speaking.