Each guide dog program has its own policies and procedures for acquiring puppy raisers. Nearly all will require that you live close enough to their facility that you can make weekly visits to the facility for training classes. So the first step is to find a guide dog school near you. See the link below of guide dog schools in the U.S. to see if one is near you.
Nearly all programs will require that at least one person work in the home so that the pup is not left alone during the day. Since most puppy raisers are children, this means having at least one parent who is home during the school day and willing to take on responsibility for the puppy's training during that time. There is a link to the Seeing Eye's puppy raiser information below as a representative example of puppy raising programs for guide dogs.
Also check with your local 4H organization. Most have a Guide Puppy affiliate.
Look for a guide dog program near you. Nearly all programs require that their puppy raisers live nearby so they can attend weekly training sessions at the facility. Each program will have their own requirements as to how to apply to be a puppy raiser.
Several organizations for the blind maintain lists of guide dog training schools. Here are a few:
National Federation of the Blind (NFB)
American Foundation for the Blind
Guide Dog Users Incorporated (GDUI)
American Council of the Blind (ACB)