When you credit the author and the work, you make it clear you are using someone else's ideas. There are many different styles of giving credit within your text. Check with your professor for the form you should follow in your assignment.
Amy Tan’s stories are often about Chinese American characters who experience conflict in dealing with their parents and their Chinese heritage and in relating to the American society in which they live (Stein 2280).
You need to list the work in the bibliography or reference list. Again, there are many different styles. Check with your professor for the bibliographic style you should follow in your assignment.
You do not give credit to anyone for ideas which can be clearly considered common knowledge:
Shakespeare's plays are considered among the greatest works of world literature.
If you don't know whether an idea you are writing about is common knowledge in your field, you can consult a subject dictionary, encyclopedia, or web source. If you are still unsure if the idea is "common knowledge," you can ask a librarian for help, or check with your professor.