In the smaller rabbit breeds a female is usually the right size to mate at about 5 months old, and a buck is ready at 6 months.
The medium size rabbits the does are typically ready to breed at 6 months old and the buck at 7 months.
In the heavier types of rabbits the doe is ready at 8 months and the buck is ready at 9 months.
But they can breed earlier particularly the males can be mature at 12 weeks in some cases so you want to alter before the earliest chance.
This site goes over spay neuter in rabbits
http://www.rabbit.org/faq/sections/spay-neuter.html
and lots more good rabbit info here
http://www.rabbit.org/care/new-bunny-index.html
Hope this helps you!
Pet Health Care, Rescue,Train,Breed
30+yrs pet vet care & nursing, rescue, behavior & training, responsible breeding, small animal care
Typically you don't do shots as you would with a dog or cat.
You can wait until the boy is 12 weeks for neutering.
You can read here about finding a good rabbit vet
http://www.rabbit.org/faq/sections/vet.html
More good info here
http://www.rabbit.org/health/index.html
If the breeder is close to you then you may want to ask who they use for a vet.