As most people on here know, I'm studding out Zero to Rubyfox's Ella in November and I was wondering if anyone could give me any advice on owning a stud dog. He will be over 2 by November

and he's just under 4 1/2 lbs.
Does their personality change that much after?
Does the marking get worse after they've been used?
Can anyone recommend any books on owning a stud dog?
Will his personality towards other dogs and/or people change?
I want to brush up on everything before I stud him out.
(before anyone asks he is registered, has a good pedigree, he's been vet checked and looked over by a judge and he's a good representation of the breed etc etc

)