I am assuming you mean the health screens done before breeding?
As a basic most check hips which can be done by PennHip as early as 4 months but best to wait until 18 months or so (approx 400+ depending on where you are) or OFA after 2 years old (can be cheaper as a dog does not have to be sedated to be done).
Elbows , heart, eyes, patellas, shoulders are all other things you can check but usually I find it depends on what people have experience with as problems in their lines what they lean towards checking. CHIC will issue a number to you if you have met their minimum requirements as well for your breed. They do not guarantee passing but they will guarantee you have done them and agree results can be published.
Last time I had elbows and hips done it was approx $700.00. We do not have easy access to a Cardiologist where I am at as we are pretty rural and for some reason while there are lots of eye clinics there aren't many/if any heart clinics.