My son won prize $ in Tourn~5k. Do I need to file a separate return for him? Whose return do I enter the expenses? Hobby section is wanting the income to be under us.

You cannot put that income on your return ... it must go on the child's return line 21 of the form 1040. 

You can report it as other income on Form 1040 line 21. Here's how to enter it in TurboTax.

·         Click the Federal Taxes tab ( Personal in the Home & Business version)

·         Click Wages & Income. (Personal income in the H & B version)

·         On the screen "Your 2016 Income Summary," scroll all the way down to the last section, "Less Common Income."

·         Click the Start or Update button for the last topic, "Miscellaneous Income, 1099-A, 1099-C."

·         On the next screen, "Let's Work on Any Miscellaneous Income," scroll down and click the Start or Update button for the last topic, "Other reportable income."

·         The next screen asks, "Did you receive any other taxable income." Click Yes.

·         On the next screen, "Other Taxable Income," enter a description and the amount. Click Continue.

·         On the next screen click Done.

The income will be reported on Form 1040 line 21 with the description that you entered.