"Blessed Are the Broodmares" is a great book, very informative. There is so much that goes on with caring for a mare and delivering a foal it's mind-boggling.
I am a little worried that you wanted your other mare bred, but don't know how to care for this one that is bred? It seems a little backwards.
Regardless, it is good you asked for advice rather than going about it blindly; if you can get a hold of your vet, they will be able to talk you through the entire thing, from wrapping the tail before expected birth, to making sure she expels the entire placenta.
If there is one piece of advice I can give you, it's to call your vet if ANYTHING goes wrong, or you could end up losing both mare and foal.