PreNatal Care of the Bitch before Mating

She should not be over or underweight. 
She should be one ( small breeds) to two years old (larger breeds) 
Larger breeds should be x-rayed for Hip displasia 
Vaccinations should be given a month before she is due to be mated 
She needs to be worm free and have no external parasites 
A Brucellosis test by your vet can be given before she is mated to prevent spreading Brucellosis to the male.

PreNatal Care of the Bitch during Pregnancy

Puppy Food
Start your female on a good quality Puppy food right after breeding. Puppy food has higher protein and fat content which her growing pups will need. It also has calcium which is important while she is nursing. 
If she is a finicky eater, discuss with your Vet the proper dosage of Vitamins and calcium content that her body requires according to her weight. Note I recommend just under the recommend dose. To much calcium can cause Eclampsia 

Dont let mom jump on and off the couch or get to much strenuous exercize duing the last few weeks of her pregnancy
The Dam can exercise and play as normal in the first month of pregnancy
In the last few weeks of her pregnancy she should not jump off couches or exert herself
A regular Vet visit to see if her hips are wide enough for the pups heads to pass through her hips.
She should never be giving any drugs or have flea products applied to her skin 

Drug table 

Drugs that can or cannot be given during Pregnancy