Velma - Go into the library and look for the book, "Poems for Scientists". Take it. Go around the house and look for the 7 symbols. Downstairs, they are in the library, on refrigerator(under paper), and the front door.
Take stool from dining room.
Be sure to look out window in living room.

Daphne - She runs into ghost of Mr.Hyde upstairs. Follow it into the bathroom and mess around with the toilet. This is where she is kidnapped.

Fred - Open the shower curtain in the bathroom and take the red towel.

Velma - Look for symbols upstairs, upstairs left, upstairs middle(over disco room), upstairs right, and in bathroom(in shower, under towel).
After you have read all 7 symbols, go outside to lab and press keypad.

Shaggy & Scooby - Go inside the house to look for food in the kitchen. Check the cabinets, find cow extract and take it. Look in the fridge, find sausage, and take it.
Go to the lab. You will then need to find a lab coat, glasses and a mustache.
Go back to the house.
Go upstairs to the room on the left, nephew's room. Talk to the boy, then try to explore the room. You will fall down a trapdoor to the basement.
In the basement, play with the robot, and it will break. Pick up the shards. You will then find a wall of cheese. Use the shards on it to cut open the wrapping, then eat the cheese. Once past the cheese, you will find a roll of electrical tape, pick it up. Go into laundry room. Use the soap suds to make a mess. Go into the next room and turn off electricity. Use the electric tape on the wires in the far room. Turn power back on and then move the levers. Go upstairs.
Go to the library. Velma's glasses are on the floor. Take them. Try to read the red book on the left called "The Secret Corridor". Try to take the book. The room begins to move. Leave the room, you will then enter a secret passageway. Look in sack, find lab coat. Look in trunk, find a key. Go back and pull book again, the room will move back.
Go upstairs to the room on the right, Helga's room. Talk to her (she will leave because of the mess in the basement) and look around. You will find a note on the bed, read and take it. There is a box under the pillow. Use the key to open it. Take the fake mustache. You can now go to the lab.

Shaggy & Scooby - Go into lab (the first room). Talk and explore.
Go to the room with the freezer in it. Take flower, it will break. Put sausage in the freezer, it will freeze. This will be used as the 4th leg on the stool.
Go into hallway and use stool under the lights to try to remove them. You will need to try twice per light, and after every two times, refreeze the sausage. On the last light, you will get a light.
Go in the house and talk to Velma.
Go back to the lab and go to the doors 1-4. Go in and out until you find the secret room ( #1 worked for me). Once inside the room, take out the light and it will not work. Now you need to get the robot to chase you here.
Go back to lab, and use hand on the robot. He will chase you into the room.
Go back to lab and take the key. Talk to Dr.Jekyll then go back into the house.
Use the key on the den door (next to the kitchen). Inside you will find a pen, use on note to Helga to create recipe.
Go upstairs to last bedroom, use key to unlock. Inside look in cabinet and find a labeler, take it. Chapter 4 - Jail Break?

Shaggy & Scooby - Go inside and go to basement. Have Scooby use the key grinder to make his nails into a key.
Go back to the lab and free Fred with this key.

Fred - Go to the basement. Get the key that is stuck in the grinder.
Go back to the lab and free Daphne with it.

Velma - At the lab, go into the room with the freezer. Open the stuck cabinet, there is a net inside. Take it.

Shaggy & Scooby - Go to the basement. Make sure there are suds on the floor, if not, use the soap. Then use the red towel to soak up some suds.

Daphne - Go into disco room and take the rope.
Have Velma or Shaggy & Scooby meet Fred outside and give him the stuff for the trap.

Velma - Ring the chime on the clock, then put the towel down the chute.
Gang will unmask the villain. Who is it?

To fool the Black Knight with a disguise: Grab the Egyptian Headdress from the pillar in the upstairs hall, then use the item in the hallway in the Egyptian room next to the picture of the two characters wearing similar headdresses. (The Knight will run away and you can grab Velma's glasses easier).
To get the key from the Museum Guard: While upstairs, get the guard's attention and let him chase you into the Art Wing. He will slip and fall and drop a key. But don't stay around too long, he'll get up after a few seconds and chase you again.
To find a secret room: Search the knobs on the velvet ropes in the art wing. Two of them will be red and each will do something different.

To fool the Snow Ghost with a disguise: Find the lump of coal on the floor in the girl's bedroom. Use it next to the group of snowmen in the snow trails. (He will leave the snow trails so you can search them thoroughly).
To find a big clue in the lodge library: Find Mr. Leech and let him chase you out of the room. Then go back in to where he was, and he will have dropped an important clue on the floor.
To get past the white wolf in the cave: Find the bone at the back of the saw mill then go back to the cave and give it to the white wolf.

To fool the Witch Doctor with a disguise: Find the lone palm leaf (frond) in the jungle trails and use it next to the group of palm trees and loose palm leaves in the Ancient Graveyard. (He will leave the graveyard so you can pick up a key he dropped in the temple).
Pay close attention to what the parrot says in the Tiki Lounge. He will give important clues you will need to find the secret room under the Mano Tiki Tia Statue.
To get the directions for the stone heads at the volcano rim: Find the cracker in the Tiki Lounge and give it to the parrot. He will give out directions that will be needed at the volcano rim to open a secret gate.

To access the door in the scary bedroom: Make sure you picked up the music box in the parlor, then when you enter the bedroom with the tentacled monster in the bed, use the music box and he will fall asleep so you can get to the door behind him. Be careful, he'll wake up if you spend too much time in the room.
To open a secret passageway: Find all of the plaques with the fish on them, then go to the den (trophy room) and arrange them on the wall in order, smallest to biggest.