I would definatly put him in a daycare, even if not on a regular schedule. It gets them used to new sights, smells, people and animals. I think anyone with a watch dog should realize its bred into them, and socializing them will not take away from that "Who is this busting up into my house at 12 at night" but help if you intend to take the dog into the public. Nothing is worse than a heaving dog (and these babies can be major heavyweights- look up cart/weight pulling) barking at someone else and their canine on a walk.
You should have the pup meet the other dogs of the family if you intend to take them over sometimes while it is a pup.
Im really happy for you, I absolutly love the breed.
Also when looking for a breeder, as stated before, make sure the parents have been tested for hip dysplacia and any other medical problems you come across (We havent had a AB in several years and I'd get their problems mixed up with a boxer (which im researching) to tell you other hazards). Just because someone says "Both Parents on Premisis" does NOT mean they're good breeders. What are the odds you're going to buy two puppies that match each other's pros and cons in disposition, size, and standard you're trying to achieve?
ABs as you know arent registered with the AKC so there are atleast two versions of the dog i can remember. i think there is a 3rd cropping up.
BUT American Bulldogs are NOT pittbulls, do not let anyone try to tell you they are because they arent and if it looks like a pitt then that is not a true AB or breeder. They should not be that small. They look like stocky, less exaggerated boxers with rounder faces less defined.
sorry for the rambling.