There is information about building in world or retrieving objects from inventory, but neither mentions how to "let go" of an object, or deselect it, having placed it in world. I find I have to select another object; other people have told me they click on the sky in order to let go of the thing they're holding. There should be some information about the approved method for placing and deselecting an object.
I didn't find the instructions helpful in regard to the difference between saving and building a scene, and thus was surprised to find none of the things I had placed were appearing in the scene when I visited it. That could do with some better explanation for the expected sequence when building an experience.
I see a lot of objects on a gridded area next to my scene, and don't see any explanation of what those are. I discovered from reading another forum that they are likely to be my objects and available for placing, but I am not clear about how they got there... nor why they appeared adjacent to my land (for want of a better term) and not on it. It doesn't seem to be everything available for the scene.
If there are ways to make the build device which is superimposed over an object when you are placing it in scene less intrusive I would be glad to have the instructions! The problem I am finding is that the device obscures the object I am placing, and in some cases it makes it impossible to see where the trunk of a tree (for example) is intersecting the land surface.