Release deliverables are stored in the installed subdirectory of each release. In that directory you can find platform dependent and platform independent subdirectories. These include directories for binaries and libraries (platform dependent), header files (often platform independent but sometimes partly platform dependent), documentation, and examples (platform independent). In particular, documentation for the packages is typically in installed/share/doc.
Software librarian also keeps a diary of the release builds. This is typically found as ReleaseLog file in the release directory. Parts of that file have been generated automatically by the release tools, while other parts may have been added by the librarian. The file may contain useful information such as how the packages were compiled, or what problems were encountered and how they were worked around.