From: east coast, usa
Three ways to see a Units' Range:
1. The Range for Ranged Units [that is, units that have a range, lol] can be seen in the screen shot below. This displays either when a unit is selected, or when a unit is moused over.
2. With a unit selected, hit 'U' to open the unit info, If the unit has a Range, you will see it there under the Strengths column on the right.
3. Select a Ranged Unit and then hover over enemy units, if the cursor turns into a 'Bombard' icon, then the target is within range.
New UI on left, Classic UI on right.