The Cotton Patch Quilt Shoppe in East Tawas, Mi (website- Cottonpatchquiltshoppe) offers many many boms through out the year- they have the most expansive list i've ever come across- seems something for everyone- including embroideries, little projects, big projects, applique, pieced, wool,...the list really does go on & on.
then there are the different sites that offer free ones every year- if you subscribe to The Quilt Pattern Magazine (which is an on-line quilting magazine) they offer a couple free ones every year- so does Jenny Beyer, Carol Doak, Sue Garmin, The quilt show (with Alex Anderson & Ricky Timms) I'm sure there are many more- those are the ones i've participated in in the past