To what address do I send Illinois state tax return? To what address do I send Federal tax return?

When you print your return for mailing, TurboTax prints an instruction sheet with the mailing address for both federal and state. If you need to look them up, use this link for federal: https://www.irs.gov/uac/where-to-file-paper-tax-returns-with-or-without-a-payment?_ga=1.31357439.1770841720.1470007833

Here is where to mail an Illinois tax return:

If no payment is enclosed, mail your return to:                      If a payment is enclosed, mail your return to:
ILLINOIS DEPARTMENT OF REVENUE                                     ILLINOIS DEPARTMENT OF REVENUE
PO BOX 19041                                                                               PO BOX 19027
SPRINGFIELD IL 62794-9041                                                       SPRINGFIELD IL 62794-9027