One of the first unit studies I ever did with David was this one on dolphins by Gwen Nicodemus. If you check out Gwen’s site, you’ll find studies on water, seeds (just the thing as we head into spring), and polar bears. These are all free, self-contained (you needn’t add anything to them, though you can), downloadable pdfs, and quite substantial. Worth a look if you need to take a little break from your regularly scheduled studies. She also has little printable science books for your Littles (a few coordinate with the studies) and some other goodies.
Cindy Downes at Oklahoma Homeschool has whole bunches free unit studies you can use in your homeschool, including the Civil War, explorers, Astronomy, insects, geology, and on and on and on. These require certain books, resources, and web access to use (you’ll need to access the plans online as well as some links).
Previous editions of Friday Freebies: