How to create such a translucent material (a sheet of paper) with some image texture? In the photo I'm directing the sheet towards a lamp and able to read what is printed on another side. What is the best way to achieve this within Blender?
You can use the transmission input on the principled shader in cycles for this. To distinguish the one side from the other you can use the input node Geometry Backfacing. Adjust the ramp node to get the thickness you are looking for.
If you need to color your translucency this could be a way to solve it. Allowing some of the light from the backside pass by adding in a Translucent shader and then mix this. By using a mix node the energy from the incoming light will be handled more correctly than with an add node.
I hope that the Principled shader will get support for color transmission in the future.