Good sites to read.....
Whelping Puppies, Breeding Dogs Dog Breeding and Canine Reproduction by Debbie Jensen. Dog Breeding and Whelping guide for dog breeders.
I'd highly encourage you to purchase Myra Harris Savant's book - Puppy Intensive Care. It's loaded with good information...from the supplies you need for whelping all the way through to birth and beyond. This can be purchased from Amazon usually less than Myra's site.
She also has seminars. There is one in PA on the 23rd....shouldn't be too far from you.
Seminar Schedule
Good luck.