Thank you for compliments, especially considering this is my first dive into photorealistic images.
I guess the biggest secret about textures is to invest into high-res bitmaps. All textures come from
www.textures.com and I purchased highest resolution available. For the lights, I have used corona sun for main illumination, on some scenes there are some dimm fake lights behind the camera to provide for additional lighting. Since the interiors are very simple I was able to invest time into setting up the light instead.
The first picture with the entrance has a "fake cloud" which dims the beginning of the entrance and some of the grass field on the right side. This was to invoke what I would call Dutch paintings atmosphere of partly cloudy landscape with high contrast of shadows and light. I was lucky to find a background sky to match this atmosphere. The bitmap comes from flyingarchitecture.com