How you do it depends on the type of the book and probably the publisher too. Many publishers will use the Harvard system, some will use footnotes, some will include bibliographies, while others don't.
The thing to do while you're actually writing therefore (unless you already have a publisher, in which case follow their guidelines for referencing exactly) is to put the quote in and keep a fully detailed note of where it came from - i.e. person, book, book title, book publisher, published date, page number of book... everything you possibly can. Then, when it comes to publishing it, you can use the information in the way the publisher requests it.
Depending on the length of quote and the nature of the book, you may also need to get permission to use the quote. Again, if you already have a publisher, follow their guidelines exactly. If you don't, provided you have all the details, you should be able to seek permission when you get a publisher (following their guidelines), although you could always pre-empt that and seek permission now.
