Hi gemma you will need to be sure he is a good example of his breed and then you will need to have all the appropiate testing done such as hip scoring,eye testing,and anything else that is relevant to his breed.
Taking him out showing or to working trials is a good way of him proving his worth and then people will aproach you to use him as a stud.
It would also be helpfull for you to talk to his breeder if you can it will help you get a good knowledge into some of the bloodlines in his pedigree and any known problems if there are any.
Being used as a stud can make a already frisky dig unbearable! plus just because he likes the toy doesnt mean he can manage to do the real thing!!
Good luck with your boy and I hope it works out for you
:)