An interesting speech by Guy Kawasaki which he has given at many high schools / colleges. The key points he stresses are on (copied verbatim from his blog entry):
#10: Live off your parents as long as possible.
#9 Pursue joy, not happiness.
#8: Challenge the known and embrace the unknown.
#7: Learn to speak a foreign language, play a musical instrument, and play non-contact sports.
#6: Continue to learn.
#5: Learn to like yourself or change yourself until you can like yourself.
#4: Don’t get married too soon.
#3: Play to win and win to play.
#2: Obey the absolutes.
#1: Enjoy your family and friends before they are gone.
Read the full speech at http://guykawasaki.com/hindsights-speech/