The American cancer society or your local hospital should have a list of groups. If there is a Gilda's Club in your area they have lots of programs. Some hospitals host them. Your husband's oncologist may have a list.
I echo GSA's advice: hospitals, including their infusion centers, and Gilda's Club. If you're in a rural area or small town, sometimes you have to look to the larger medical centers, including the teaching hospitals, to find more availability of support groups.
I also recommend this magazine - I've found it very helpful. It includes a range of very technical medical issues as well as common sense practical ones.
curetoday website