From a vial, if you want to take 1cc out, then you have to fill the syringe with 1cc of air .Then you insert it into the vial, and inject the air to create a vacum, then turn the vial upside-down, and extract 1cc of fluid. Take a little extra too, then remove it from the vial. Keep the syringe upside down and flick the bottom of the syringe to force the air, if there is any, to float to the top. Then push the plunger to expel the air and some liquid, get an alcohol swab, rub down the pin and the injection area thoroughly. Then in the words of Jenna Jameson "Stick it in!"
Some ppl like to replace the pin because they say it dulls out after it goes through the rubber stopper. But I never had a problem and I never seen my Dr. nor hospital personel do that when injecting a patient. So, w/e.
From an ampule, just be patient and put the syringe all the way in and slowly draw the liquid. Some ppl use different guage pins to draw to prevent glass particles from getting in the syringe. If you break the ampule correctly, you shouldn't have a problem.
I hope that helps. Anyone with more details or w/e, chime in.