I do not have a diagnosis, but after a bout of ON, I read this book:
Multiple Sclerosis- New Hope and practical Advice for people with MS and their families by Louis Rosner and Shelley Ross
I was given this book (also good) Multiple Sclerosis- The First Year by Margaret Blackstone
I figured I would arm myself with knowledge since there was a large waiting period between the dx of ON and the MRI. I don't regret reading either book, even without a dx. I particularly liked the first one.