I have a son who is similar and I've been reading everything I can get my hands on for the last two years. The 8 Keys book is the best I've read because it is the only one that provides detailed advice about how to scaffold various social skills. If you want to read a book that is reassuring and can give you some perspective about how things might work out in the long-term, check out The Way of Boys by Rao Anthony.
For us, finding somebody who my son could connect with has been key to improving his social skills. The psychologist who did the initial screening and school observation told us that my son's social issues would disappear if he were with kids who were his peers. That was hard to believe at the time but it turned out to be true. Once my son met a couple of other gifted kids who had similar interests, he was much more interested in engaging and interacting. That seemed to provide both the motivation and opportunity to practice social skills and the gains he has made seem to translate to his interaction with other, more "normal" kids, even if he does seem more quirky when he is around them.
My son also participated in a social skills group for over a year but we saw a much more dramatic change once he changed schools and had a few peers in his class.
