To acquire the Book of Nature you must sell at least one of every piece of gear and consumable item in the game to the item shop. Use the Book of Nature to receive a password that can be used in Wizardry Gaiden 3 to "import" your party members there.
Sound Test And Monster Viewer
Go to the training option, and create a new character. As the name, enter a space, followed by -WIZ-, and then another space. Hit End, and you'll be taken to a Monster Viewer and Sound Test.