Much of this has been collected in popular form  in Legends of the Jews, by Louis Ginzberg; see particularly its first chapter  discussing esoteric and mystical concepts such as Paradise, and the "higher" Gan Eden.
A substantial part of this information is found in a popular form within Legends of the Jews, by Louis Ginzberg. The first chapter focuses on esoteric and mystical topics including Paradise, and the "higher" Gan Eden.