The next question then is, “How do I get permission for those quoted passages?” If the quote comes from a book, check the copyright page to see if the book is copyrighted in the name of the author or the publisher. If in the name of the publisher, write them directly to ask permission. If in the name of the author, write the author and mail the letter to the publisher asking them to forward it to the author. They aren’t likely to release the author’s address to you.
When seeking permission for any use, you need to be very specific about what you are asking for. They will need to know how you will be using the material, and the exact quote you want to use (starting with this phrase on page x and ending with this phrase on page y). If it’s going into a book, ask for permission for this book, plus all future revisions and editions, and nonexclusive world rights in all languages. That way you don’t have to come back and ask permission for each new edition.