Connie -
Welcome "aboard!" It sounds like you have the right idea: thrift shops, Goodwill, estate sales, etc. The coupons in the mail for Joann's, Hobby Lobby, and Hancocks are also very helpful. I think HL also has coupons online from time to time; you just have to keep an eye on their website.
I'm one of those men who quilt. Actually, it's something my wife and I do together. You'll see Eddie on this board a lot and he makes some great quilts, and lots of them. There are a few others of us on here also.
I think it's great that you are taking on the project of teaching kids to sew and quilt, especially the ones who have special needs.
I hope you enjoy your new hobby and job. Merry Christmas.
Darren