If I outline, I keep my outline simple, and keep referring to it. It is the road map through the joinery of my story. Basically, I tell my story in three stages: (1) the introduction, (2) the expanding on the introduction, and (3) the solving, or closure section. Think of your book as needing a beginning, middle, and an end.
BEGINNING: Chapter one introduces all the characters and who has a problem. If the character does not enter the story until later on in the book, I make reference to him or her in chapter one. For example, in my next novel, Daughters of the West Mesa, I introduce such a character in the first chapter by noting my lead character has a message for him on the telephone answering machine. She ignores the message and does not call him until chapter three. Chapters two, three, four expends on the problem or needs of the characters. All the characters need something.
MIDDLE: Chapters five, six, and seven hint at how the characters try to solve their problem or need.
END: In the ending chapters seven, eight, and nine, each character meets their need and/or solves their problem. I call this the-killing-off-of-characters section. The last chapter, the end, places closure on the entire book. I then review my outline making sure I included the main points.