The first place to look is the classifieds of your local newspaper or even your local city page on Craigslist.
Don't forget to check out online classified sites, such as Craigslist, a veritable swap shop for cities all over the country.
Link san francisco bay area education/teaching jobs classifieds... craigslist education/teaching jobs classifieds for san francisco bay area.. .
Freecycle, Craigslist, and a thousand message boards achieve the same outcome.
You can peruse ads from people all over the country at online classifieds, such as craigslist, and you'll often find some great deals!