THE INTERNET
From online math tutorials to educational games for every level, the internet is the biggest free source of educational materials.
www.starfall.com a fun resource for teaching reading to young children
www.funbrain.com
www.primarygames.com
www.kidsgames.org
THE LIBRARY
Books, films, dvds and cds can all be borrowed at the library free of charge. Take advantage of story hour and other free activities as they are offered. A weekly trip to the library should be on every homeschooler's agenda. Your child will learn all about research, the different types of media, and most importantly will develop an interest in books.
OTHER HOMESCHOOLERS
Many families swap materials or give away items that their children have outgrown. Be sure to develop relationships with other homeschooling families or join a coop. This will ensure a new variety of ideas and materials at your fingertips whenever you meet.
EBAY
If you're looking for resources such as pre-packaged curricula, check ebay before you buy from another source. You may get a better deal here than anywhere else.
TEACHERS
Friends or family members who are teachers will love sharing worksheets, books, and dated curricula with you if you just ask. Teachers love to clear out stuff they're not using because space in the classroom is valuable.