As a US citizen you are taxed on your world income . Thus you must declare yearly all your income including rental income from properties abroad. The rental income/ expenses are reported on schedule-E -- the only difference for you is that foreign property are depreciated over 39.5 yards ( TurboTax will do this for you when you tell it that the property is foreign.
When dispose off the property , the transaction is treated just like it was on US soil.
All reporting is in US$ and generally the dollar of the day is used but many use the monthly/ quarterly average -- use any published source ( keep notes/ records of what you used).
If your tax home is abroad ( 330 day out of 12 months you are abroad ), while your foreign earned income ( active income ) is excludable up to a maximum, passive income are not eligible for such treatment. If the local taxing authority also taxes this non-excluded income, then you can use foreign tax credit or tax deduction ( this last is still unclear for 2018 on wards ) to reduce the effects of double taxation.
Can the IRS find out , if you do not report ? ---- suggest you assume that they will ( besides, when you file you are attesting that it is true to the best of your knowledge).
Good Luck
