Matching a mare

Just wondering if anyone can help. I am starting to take an interest in NH breeding lines, the idea is to maybe take the plunge and try breeding my own. Its a long way off and initially I was wondering how do most serious breeders find the best matching sire to their mare, I know for top class flat horses there is a site called "gold Mine" which has this facility, but how is it done for NH horses? My other question is, is there a book out there that covers the fundamentals of pedigrees and breeding that anyone can reccomend? I see there are a few around but all seem to be based on american racing, ideally something British and on NH horses.

Thanks