Check out this Mayo Clinic podcast, in which Dr. Shakila Khan runs through all of the issues surrounding bone marrow transplants, from registering to donating to receiving the transplant itself, in detail. The specific case she discusses is a little girl suffering from aplastic anemia, but everything she mentions about registering, donating and receiving are the same regardless of the disease.

Despite all the research on bone marrow transplants I've been doing for the last few months, I still learned something new: unlike other forms of transplants, the recipients of bone marrow transplants don't need to spend the rest of their lives taking immunosuppressive drugs to counteract the effects of the transplant itself (which is kind of obvious when you think about it, since marrow produces the lymphocytes and leukocytes that make up part of the body's immune system). Definitely worth a listen.