For the stone Tablet, you must find a rectangular stone. Flip and it should look a bit like a Yoshi. Run around it (in 3-D) once. The stone Tablet should appear on 'Yoshis' head.
For the water Tablet, go to the start of the chapter(5-2). keep going right until you reach some water. Sink to the bottom-don't worry, you won't die-and if you can't see a chest then flip, and open it. The water Tablet should be inside.
For the fire Tablet you must find a place where there is a Crysra (I think it's Purple). If you flip you should see tons of ? blocks(Hit them if you want to). Then in 3-D go left(there should be a path to follow). Once you reach the end of the path flip back into 2-D. Go right until you see an unlit fire. Switch to Bowser and light it. Then you will see the fire Tablet.
Hope this helps!
It's Chapter 1.
It's in Chapter 7.
Chapter 4.
Chapter 1-1
By getting dottie
You will "find" him after chapter 6.
go to bestouvise in chapter 1-1
It is 5963
It is 5963
Easy just ride the boat
in chapter 7-1
Just take it to a locked door.