Typically include the author's name, the year published, and the page number (if applicable).
Example: (Hildenbrand 1999:47)
If the author is mentioned by name in the preceeding sentences (e.g. "According to Hildenbrand...") leave out the author's name.
For a Book
For a Journal Article
Author Last, First. Year of Pub. "Title." Journal Name volume # (issue #): inclusive page numbers if available.