Well you can apply immediately but expect to wait a few months before you actually get your card. Before mailing out your application & doctor recommendation, make a couple copies. Those copies are going to be what you use in dispensaries/etc...

I would recommend NOT assigning a caregiver, at least not at first. You can always assign one later if you find a place/someone you really like.

Also make sure you have copies of your medical records to bring with you to your doctor's appointment. The doctors are getting stricter with requiring them. It sounds like your husband will definitely qualify, but just cover your bases and bring in copies of his records & current meds.