Message in a Haunted Mansion

Adventure Lantern: Message in a Haunted Mansion
Full-fledged walkthrough with illustrations.
http://www.adventurelantern.com/walkthroughs/nancyDrew3/nancyDrew3.htm

Low-Spoiler Guide to Nancy Drew: Message in a Haunted Mansion (PC)
Hints, walkthrough, and game advice, all without giving away the plot or the puzzle solutions.
http://www.angelfire.com/hero/tjekanefir/drew-haunted.htm

UHS: Message in a Haunted Mansion
Select questions from the game and view hints in increasingly detailed steps, from gentle nudges to full answers.
http://www.uhs-hints.com/uhsweb/ndrew3.php