A bazillion free classified ad sites are out there.
Most don't allow "store ads" however, I have posted 1 item within my store as "for sale".
Read all the "rules" for each of these.
This is the "big boy". You can only post 1 ad in 1 city for the same thing each week.
However, for my Candy Bar wrapper site....
I may select 1 city, post a "for sale" 100 custom wedding favors for $xxx ... see http://www.candybarwrap.com/ for designs.
then in another city .... "for sale" 100 custom Birthday candy bars for $xxx ... see http://www.candybarwrap.com/
OR from http://www.promote-101.com/ , I post "golf stuff" in Arizona & t-shirts in another city.
You get the jist.
Here are a few to start with....
When I google "free classified" I get over 19 million results.
So use your wordpad, develop an ad & start copy & pasting.
BE SURE to read the rules for different sites and remember that MOST offer free for 7 days & want you to pay for 30 day ads.
You decide but I, personally, use free & relist each month or so.
Set up "free ads" in your bookmarks & each month you can quickly find all those free classified sites.
Happy Promoting all :)