The book needed to locate realistic trade in values would be the "NADA" book. This is a monthly publication and is usually found in the "reference" section at your area library. The book typically used at the dealer is known as the "Black Book", whick is a wholesale/trade in booklet used by almost all dealers. Some use the NADA book as well. The prices should be very close to one another. This will provide you with a closer number to "true" trade in value. On the other hand, the dealers will play a number game with you, when a trade is apparent at the beginning of the deal. The best way to avoid this, is to negotiate the deal without a trade in involved. Then once the numbers on the new car are confirmed, tell them you have a trade in and ask what is the value for your trade. This way you will have a realistic idea of what your car is worth. I have the best luck in dollar return by selling my car to private individuals. If you truck is as nice as you state, you should have no problems selling it yourself. Good Luck!