Three new picture books about Thanksgiving should delight young readers this season:

THANKSGIVING TREAT by Catherine Stock. Bradbury Press, 1990. $11.95.With the Thanksgiving preparation in full swing, a small child asks, "Can I help you?" But each time he is sent away with "Careful, the oven is hot," "You're too little," or "Go see if you can help the boys."

Grandpa finds the perfect job for small hands, picking up chestnuts to roast in the fire.

Stock has captured the holiday events through the voice of a child and young readers will relate to the downcast eyes and "not big enough" feeling. The sensitive watercolors add much to this Thanksgiving treat.

'TWAS THE NIGHT BEFORE THANKSGIVING by Dav Pilkey. Orchard Books, 1990. $13.95.

"Twas the night before Thanksgiving

And all through the trees,

The fall leaves were spinning

Aloft in the breeze . . . "

This is a spoof on the famous Clement Moore poem related to Christmas. Pilkey has written and illustrated a chuckle-a-page about children who visit a turkey farm on a field trip. When they reach the farm they meet the Farmer Mack Nuggett:

"He was dressed all in denim

From his head to his toe,

With a pinch of polyester

And a dash of Velcro . . . "

and the turkeys are called by name:

"Now Ollie, now Stanley, now Larry and Moe,

On Wally, on Beaver, on Shemp and Groucho!"

The children and turkeys have a fine time together until they find out the fate of the birds.

When the children board the bus they are "calmer and mysteriously fatter!" What Mack Nuggett and the teacher can't see is a fat turkey tucked under each sweatshirt and coat.

The next day,

"They feasted on veggies

With jelly and toast,

And everyone was thankful

(The turkeys were most!)"

`TWAS THE NIGHT BEFORE THANKSGIVING will be chanted by children and loved for this holiday and throughout the year.

THE DRAGON THANKSGIVING FEAST: THINGS TO MAKE AND DO by Loreen Leedy. Holiday House, 1990. $14.95.

The 10 little dragons will probably be familiar to young readers from "A Dragon's Christmas: Things to Make and Do," "The Dragon Halloween Party," "The Dragon ABC Hunt," and "A Number of Dragons." In this one the dragons prepare a feast for Thanksgiving but stop to give directions to eight creations: wild-bird feeders, popcorn holders, napkin rings, as well as recipes and games.

The antics of these multicolored monsters are clever and humorous. But it is the `things to make and do' that will capture the interest of children.