My son cannot e-file because he was only 15 when he was working. Can I print my tax documents from TurboTax so I can mail them in?

Yes, you can print your tax return and mail it instead of Electronically Filing your return. 

1. Open or continue your return in TurboTax Online if you haven't already.
2. Select File,
3. You'll now see 3 steps. Complete Steps 1 and 2 if you haven’t already done so, then select Start next to Step 3.
4. On the Let’s get ready to e-file screen, select File by mail, then on the next screen make sure you select File by mail for federal and all of your states.
   • If the File by mail option isn’t available, you probably previously selected to pay your TurboTax fees through your tax refund. In order to file by mail, you’ll need to pay with a credit or debit card. Here’s how to change your payment method from pay by refund, to pay by credit or debit card. Once you change your payment method, you'll see the File by mail option as described above. Select this and continue to Step 5.(If you're using the Free Edition of TurboTax: You obviously won't have to pay, but you'll be asked to register. Just follow the instructions on the screen after selecting File by mail as above.)
5. Follow the instructions to print your return. If you haven't already paid any outstanding TurboTax fees, you'll be prompted to do so before you can print.

The filing instructions document will print out with the paper copy of your return.  For your federal return, you can also look it up at this IRS website.