A book may be good for a general overview outlining duties and responsibilities as well as CRM. However you are your own individual who has your own style. Think about all of the captains you have flown with in the past... both good and bad. Think about how you like to be treated as a F/O. Take all of those qualities and adapt them to your style. Captaining can't be tought... it's inbred from the first time you solo. That's where the fundamental building block for being a captain starts.