first off, thank you for asking.
that being said, firstly of everything i would seriously reconsider bulldogs. theres a reason the average price for a good "english" bulldog is so high. ive YET to meet a good bulldog breeder that didnt preschedual a c-section and have never met an english bully thats had a natural birth, c-section is a give and expect it to cost anythign from
$1500 to $3000.
then you have the cost of puppy shots, tail dock, dewlcaws, multiple checkups.
if you are making ANY money when breeding any breed your cutting corneres somewhere, ESPECIALLY with english bullies who are notorious for health poblems .
that being said, to realy answer your questions as such. on breeding ANY dog.
a female should be bred no more than everyother heat (once a year), with a breed like the english bullies id say no more than every 4th heat (every other year) and that is the max, preferably youd wait longer, the longer the dam has to rest between litter the better it is for her and the pups. At no older than 6 yrs she should then be retired, spayed and give the rest of her life living in your home and heart as a pet and frined!
Puppies should live with you will at least 8 weeks, during that time you going to have to feed the, start socilization, traing, housebreaking, and spend a fortune feeding them because they need HIGH QUALITY puppyfood (nothing you can buy from the grocery store ect) and finding homes for those puppies tends not to be as easy as it seems, ANYONE can advetises such and such a puppy for $50 to "good home" but a real breeder doesnt just trust that the person is a good home, instead they spend time doing refernce checks, home checks, meetings.
There should be a spay/neuter contract AND a clause somewhere in there that in any situation the person cannot keep the dog it comes back to you.
as breeders were essentially "playing god", we are creating life and are responsibel for that life untill it is over.
when my chis whent to their homes it was 100% undersood that in any situation it wasnt working puppy comes back to me, i am 100% responsible for that puppy even after its left home. you have to be willing to deal with phonecalls at midnight from a worried puppy owner when their pup wont stop crying, and be there to answer questins throught the dogs life...
but were jumping ahead.
before your ready to breed you have to know about your breed of choice. Make yourself VERy familiar with your chosen breeds AKC standard, join the breed club related to that breed, and learn about its personality, size, pros cons, temperment, attitude, training, handling...you want to be able to answer ANY question about your chosen breed with confidence that your not steering anyone wrong, because when you start breeding youll have to answer all the questions your buyers can throw at you...
once you feel you know your breed, find a SHOW breeder, someone how competes with their dogs and see if they would let you aprentice under them, see if theyll teach you to handle the dog in the ring, with the help os an experienced breeder youll learn about the genetics behind breeding, reaserching family lines and what to look for in a good dog. often theyll let you handle their dogs and even assist in whelping. id suggest doing that for at least 4 litters (or 2 yrs) before even thinkign of branching on your own.
another thing to keep in mind, most good breeders specialize in 1 breed, they often will have a very small number of breeding dogs, 2 males and 4 females or so, some even less.
hope this helps some!