Do I enter foreign earned income netto or brutto? Can I use today's exchange rate when I convert my foreign income (EUR) to USD?

You use your gross income (brutto) when entering your foreign earned income.  To convert your income from Euros to dollars, go to this IRS site:

https://www.irs.gov/Individuals/International-Taxpayers/Yearly-Average-Currency-Exchange-Rates

To enter foreign earned income in TurboTax, please follow these steps:

1. Click on Federal > Wages & Income  [Personal > Personal Income in TT Home & Biz]
2. In the Less Common Income section, click on the Start/Update box next to Foreign Earned Income and Exclusion. 
3. On the screen Did You Make Any Money Outside the United States? mark Yes and click Continue. 
4. On the screen What Form(s) Was Foreign Income Reported On? mark the selection that applies and click Continue.
5. Continue through the screens, entering the requested information.
6. TurboTax will tell you if you qualify for the Foreign earned income exclusion.