Check with travel agents and the Chamber of Commerce for free maps. Pencils, pens, paper and notebooks. Often, you can find real bargains, so stock up when the price is right. Some of the restaurants offer a small pack of crayons and coloring books to their small patrons. Save these for art projects.
Butcher paper makes excellent drawing and painting paper.
Save old newspapers for drop cloths during finger painting. Calculator, protractor, compass. Calculators are also often given as free promotional materials by some companies. Be sure to ask your bank, insurance agent, car dealership, and other businesses where you have an association for any items they offer that might be of use. Look for blank tapes on sale, and prerecorded tapes at video stores, thrift stores and yard sales.