I need to report a rollover from a 401A to a Roth IRA account. Where do I do that? I've tried "Retirement Plans and Social Security" as instructed, but no luck there.

You should have a Form 1099-R reporting the rollover. 

Report your conversion from your 401A plan to a Roth IRA as follows:

1. From the federal menu in TurboTax navigate to Wages and Income
2. Find the Retirements and Investments or IRA, 401(k), Pension Plan Withdrawals (1099-R) section 
3. Select Start, Revisit or Edit/Add next to IRA, 401(k), Pension Plan Withdrawals
4. Indicate that you did get a 1099-R statement if necessary
5. Select how you want to enter your 1099-R statement (import or type in yourself) and enter your 1099-R information in TurboTax
6. On the screen that says Tell us if you moved the money through a rollover or conversion indicate that I converted some or all of it to a Roth IRA
7. On the screen that says Did you convert all of this to a Roth IRA indicate that you did

Answer any additional questions in that section.