Good on ya for doing this.
I work w/ deaf dogs (yes, dogs that are deaf, not dogs for the deaf). They are trained in a very special manner and then they are adopted out. We work w/ them to get them socialized to everything, often times deaf dogs are frightened and aggressive due to their handicap. Deaf dogs, as with a dog for special needs, hand signals are important. I know for a working dog that they need to be socialized but then they need to learn not to be distracted by outside sources because they have a task at hand. That can be hard because people always want to pet a dog.
You will need lots of time and energy in order to work and train them. It is like having a new born. Temperament is very important as not all dogs are suitable for people with special needs. There are many web sites that provide excellent suggestions for training, but if you are working with a group they should also be providing you with all the necessary tips. In particular, each group has its own training program that they are generally known for, so work with that and supplement with research.
It can be sad when you get to the point where you adopt the dog out, but there is such great joy in seeing your work accomplished and the joy that another person gets from the dog (in your case, the special needs individual getting a great dog and help).
As for toys, the simple ones are the ones they love the best. I find that if you have an old sock and tie it in a knot they love that. You can take an old ball and put it in a sock. For a puppy, they generally lose their baby teeth w/i 4 months and those early teeth are VERY sharp and very tough, so they have a tendency to want to chew, chew, chew .... that is why an old sock w/ something in it for them to chew is good that way they don't destroy things by mouthing/teething them.
I am so happy for you. Enjoy the time you have. It is amazing. And from experience, give it time, you will not be so tired as the puppy starts to get older. But I understand the lack of sleep my current guy is only 3 months old and in the beginning it is very slow going and very tiring and I have help because I work a full time job that is pretty time consuming, so I have someone who comes in the middle of the day and works w/ my guy also. But I get around 5 hours of sleep a night. But honestly I cannot imagine things being any different.