I'm not sure what my parents did for me apart from somehow making me hugely interested in anything and everything. I've never had a work ethic (unless I'm fascinated by something), that would have been handy. I believe that encouragement to work, by praise, reward, whatever is key to success, but not to the exclusion of fun, as that's also very important.

They also need to be aware that it'll cause them some social problems with some types of people (to some extent depending on many factors), and they need to be prepared for that, or at least supported through it. Close friends may also help.