Among all suffixes, -san is the most neutral; adults, male or female, use -san for each other.
-chan and -kun indicates more intimate and casual relationships if used by adults addressing adults. Kids and teenagers use -chan and -kun for each other, and adults also use -chan and -kun to them.
-sama is a bit different. The situation is limited, but in those situations, -sama is necessary. We don't use -sama just because someone is in higher status. For example, President Obama is Obama-san or Obama-daitouryou(means president), not Obama-sama unless the speaker wants to express personal worship to him.
So these are the situations we typically use -sama.
-from sellers to customers
-in formal business letters
-to the emperor(tennou) and his family