In 1998 I started selling garage sale items that made a nice little profit...mostly children's toys. Toys are great to sell...must be clean and in nice condition ( a child will get these!) I particularly search out children's books from garage sales as parents are anxious to clean out their garage and often accept an offer.
In addition,I have a huge reading habit that costs a lot...but most of my books resell nicely on EBAY...I read the NY Times book review every Sunday...and rush to the computer to list books I have from the reviews.
recently I've been selling books book at garage sales...but I've also begun to trade my regular books in at used book stores to get more sellable books.
It's best to sell something you enjoy! Happy selling