The library has all sorts of craft and activity books. The children's librarian can help you find something age appropriate. Many books have games and projects that use materials you probably already have around your house.
I also keep a stock of craft supplies on hand and let my kids come up with their own ideas. I recycle stuff to put into the art closet. Here's a sample:
-large cardboard sheets, found between toilet paper pkgs at costco. good for posters or making play houses.
-gallon of glue, cheap at the hardware store, pour into a small paper bowl and apply with a popsicle stick.
-fabric scraps
-wrapping paper scraps, cut into squares for origami
-junk mail, use the back side of the colorful paper.
-old national geographics, great photos to cut out
-drinking straws from the dollar store
-any odds and ends like buttons, feathers, shoe laces for collages.
-old shower curtains, when the little holes break at the top, they become drop cloths to protect the floor for messy art.
Now is a great time to make Christmas ornaments. You can cut out shapes from cardboard, glue beans and peas in a pattern or not, edge in lace or gold ribbon. Make picture frame ornaments from popsicle sticks in a "squarish" shape, add decoration like sequins on top, glue a photo of your child in the center. Fimo dough is on sale this week at Michaels, shape, poke a paper clip into the top for a hanger, bake. Cut and/or roll scraps of colored felt into pretty designs. Make sure you mark the child's name and date with a sharpie pen onto the back of the creation. Our tree is full of these treasures. Send me a message and I can send pix.