How does drug dealing work?

For your sake I hope your question is strictly rhetorical! .... Or are you one who thinks you're too smart to get caught!

You could also study pharmaceutical chemistry at university, register with the relevant professional body passing any exams they require to become a registered pharmacist and legally "deal" drugs. The pay is very good as well. Currently in the US a pharmacist earns on average $104,260 per year. No chance of going to jail either.