What were the clues that helped the Mystery Inc.solve the mystery of Spooky Island in the 1st Scooby Doo film?

Well, they found the Daemon Rightos (no IDEA how to spell that), the golden pyramid-shaped item, which was the most important thing about the case. It had instructions written on it about the ritual, and the monsters... basically it outlined the whole plot once Velma translated it. Velma also figured out the monsters can't be in sunlight, so I suppose that could be considered a clue. I know it definitely helped Mystery Inc. to win.