I agree- craigslist is a good place to try, you can post pics and list the type of fabrics.
You could look into whether your city ever hosts any rummage sales or quilting shows and try to get a booth. Or maybe a local farmers market where you could do a one time sale?
Maybe if you have enough stuff, you could host a garage sale? Or be a part of someone elses sale.
Or look up other people who sell homemade crafts and tell them what you have to offer- maybe they will even do a trade of sorts, your raw materials for a few of their finished products?
Maybe a re-sale shop for kids clothes or some other kind of consignment type shop would take the stuff on consignment.
You could google some first-time mom sites and list the materials and possible things that can be made from them- alot of stay at home moms like to do crafts (as do grandparents) and they may have the time and desire to take on some new projects for the little ones. (bibs, burp clothes, diaper covers, dresses, etc)