If a choking person becomes unconscious, what steps should be taken?

Learn CPR: I recommend you contact your local red cross or american heart association and take a CPR course. If you go to google you can look up CPR anytime and there are resources where you can watch and learn at home.

CPR: You can read up on this topic all you like, but hands-on training is the best and most effective policy. CPR does teach choking as part of their program.