If you are mailing your returns, you want to attach all W-2s and 1099s that have federal tax withheld. Make sure to sign the return as well. There should be a Filing Instructions sheet that prints with your return and it should state what to mail with the return and where to mail it as well. If not, see below for where to find address you need to mail the returns to.
For state returns, you need to check your State Department of Revenue website to get the address you will need to mail your state return to. You can go here https://ttlc.intuit.com/questions/1901670 and select your state and it will take you to their contact page.
