Chevrolet Master Parts Catalog (find one a couple years newer that your vehicle so any late year changes are shown).
Chevrolet Parts, Truck Illustration and Special Information Catalog. Exploded illustrations show how things went together and where to find the part number in the Master Parts Catalog.
1955-59 Chevrolet Truck Factory Assembly Manual.
Chevrolet Passenger Car and Truck Accessories Instruction Reference Manual.
Chevrolet Truck Shop Manual. Many years are covered with a Supplement Shop Manual (only covers new changes), so you'll need all prior Supplements AND the first Shop Manual in that series for full coverage.
MOTOR Truck Repair Manual (Green Cover). They came out annually and covered a ten year span, so find one that has your year covered.
60 Years of Chevrolet by George Dammann 1972, Published by Crestline Publishing Co., ISBN Number 0-912612-03-7. Lots of history, production figures and images from 1912 thru 1972 cars and trucks.
Chevrolet Truck Data Book (Dealership/Salesmen's Book), has all the spec info on the trucks.
Chevrolet Truck Selector Catalog for Salesmen, what the salesman carried in their pocket.