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.
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.
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.
curetoday website