my son (a student) received a 1099-misc but the only box that was filled in was an X in box 9 that states the newspaper supplier made sales to my son for over 5000.00 for resale - he is 21 years old and I claim him as a dependent on my return - he received a w-2 from another job for 680.00 wages he earned - does he have to file a return? And if so how does he go about this?

thanks Dom

Yes, he must file. His filing status is Single dependent that is he will not get exemption of $3,400, but he will get standard deduction up to $5,350 of earned income. 1099-MISC income is earned income.

1099 income is Self employed income. He will file schedule C. On the net income (after deducting expenses), he will pay SE tax at 15.3% for that he will file schedule SE.
Read:
Tax News: Independent Contractor or Self Employed Person getting 1099 (instead of W2)