I taught my self both how to probe and pop snakes. My vet did tell me how to do while holding one of my BPs but she wouldn't actually probe the snake unless I paid her to do it as part of the exam. I tried it myself but not with out someone telling me about it first with a snake in there hands.
Dr. Seaward has a sexing video for sale on the net and I once found video that could be downloaded from the net showing to herpers sexing a ball and explaining how to do it. Maybe you can still find it through a google.