The Homeschool Buyer Co-op is a free homeschooling organization for both new and veteran homeschoolers. Co-op membership is free and confidential, and entitles homeschooling families to GroupBuy discounts on high-quality curriculum. On the site you'll find lots of free information, such as databases of free curriculum, field trips, and educational contests and scholarships. Highly recommended. Click here for more information.
I have been a member of Homeschool Buyers Co-op for several years; they have some great deals. Last year I purchased Rosetta Stone- Italian for my son at a great discount and earned Smartpoints which can be redeemed for other curriculum.
Right now they are running their Summer Fun Reading Program which gives your kids the opportunity to log their daily reading and be eligible for the prize drawings; go check it out and sign up - it's free! There's nothing to lose!
Oh, did I mention that the grand prize is an Apple iPad??