First, visit the style guide that you'll be using,and see which pieces of information should be included in your book's citation (author, date, chapter title, book title, publisher, city, etc.), and in what order.
Then, find the pieces of information in the book itself.Most of the information will be on copyright page, but you may need to check the table of contents, too (both are within the first few pages of the book).
Author or editor name: Look on the book cover and copyright page for author or editor names.
If you are citing a chapter that was written by someone other than the book's editor, look in the table of contents, or on the first page of the chapter that you're citing.
Publication date: Check the copyright page. If more than one date is listed, use the most recent one.
Title: The book title will be on the outer cover and on the copyright page.
Chapter titles will be listed in the table of contents, and on the first page of the chapters themselves.
Page numbers (needed for chapters only): The table of contents will give you a chapter's first page number. To find the last page number, flip to the end of the chapter and look at the top or bottom of the page.
Publisher (and publisher location): The publishing company's name and city will be found on the copyright page. Publisher name may also be printed on the cover.
Take a look at these examples (click images to view larger):