Here is a breakdown:
agricultural products (soybeans, fruit, corn) 9.2%, industrial supplies (organic chemicals) 26.8%, capital goods (transistors, aircraft, motor vehicle parts, computers, telecommunications equipment) 49.0%, consumer goods (automobiles, medicines) 15.0% (2003)
2006 U.S. Govt figures
from wiki
Exports $1.283 trillion f.o.b. (2008)
Export goods industrial supplies, 29.8%; production machinery, 29.5%; non-auto consumer goods, 12.4%; motor vehicles and parts, 9.3%; food, feed and beverages, 8.3%; aircraft and parts, 6.6%; other, 4.1%. (2008)
Main export partners Canada, 21.4%; Mexico, 11.7%; China, 5.6%; Japan, 5.4%; Germany, 4.3%; United Kingdom, 4.1%.[7]
Paper doesn't even register.