These I feel ought to be done on every adult dog before being bred:
 
A very careful and thorough physical exam by vet
Complete Blood Panel
Bile Acid Test
Brucellosis Test (every time before breeding) 
And these are the Health certifications available. It's very impressive to me when a breeder goes further than the basic health testing I mentioned above and gets their dogs certified for any of these things. If I ever decide to show and breed, I'd probably look into most of these for my dogs. 
Patella and hips cleared & certified by OFA 
OFA: Patellar Luxation 
OFA: Patellar Luxation
OFA: Hip Dysplasia  
OFA: Hip Dysplasia
OFA: Legg-Calve-Perthes  
OFA: Legg-Calve-Perthes 
Eyes checked & cleared & certified by CERF
CERF - Canine Eye Registration Foundation  
CERF - Canine Eye Registration Foundation 
Heart checked & cleared & certified by OFA
OFA: Cardiac Congenital Disease  
OFA: Cardiac Congenital Disease 
Thyroid checked & cleared & certified by OFA
OFA: Thyroid  
OFA: Thyroid 
Ears checked & cleared & certified by OFA 
OFA: Deafness  
OFA: Deafness
(personally, I think this probably isn't needed for our breed..) 
You also want to do research into the pedigrees of the male and female to check for any genetic defects/diseases to identify if the dogs could be a carrier or not.