This is a difficult question to answer concisely, but in general, here are several aspects of Hawthorne's version of Puritan communities as portrayed in The Scarlet Letter.
1. Hypocritical: It is not by accident that the author chooses a Puritan minister to be the mysterious father of Hester's illegitimate child. He strives to show that not only is Dimmesdale able to deliver masterful sermons from the pulpit while struggling privately with his sins, but his parishioners are easily fooled by his outward purity because they base their opinion on the visible aspects of a person.
2. Judgmental/Self-righteous: The townspeople think nothing of condemning Hester publicly nor holding her sin against Pearl when all of them struggle with their own sins. Hester recognizes this as she matures and becomes more at peace with who she is. She knows that each person has his/her own scarlet letter, but that they simply aren't as visible as hers. When the Puritans can judge and punish others, it makes them feel better about themselves and their "purity."
3. Superficial: Because the Puritans seem to study the exterior others and disregard their true character, they place value on unimportant elements such as Rev. Dimmesdale's good looks, fancy, ornate clothing (such as Hester sews for them), and Chillingworth's seemingly innocuous appearance. Only the characters who have practiced self-examination such as Hester and Chillingworth look at people for who they really are.