if 36 bucks is a problem not be rude but dont worry about breeding clowns. you are going to spend ALOT more then that.
i have the book and if you want can sell you mine for 20+shipping i dont use it anymore. but like i said it cost money to raise clowns and unless your doing it on a large scale it if not very proffitable.
as for your question. it will take as long as it takes. it can take 6months, a year or longer.
you have to have the condition proper to help along the spawning. but even then there it is not a sure thing they will pair up. do not expect to toss in three clown and in 2 months see eggs. although i'm sure that can happen in 99.9% of the cases it wont.