answered Aug 12, 2009 at 05:11PM
In the arm, the three veins are the brachial, cephalic, and median cubital. On top of the hand, it is the dorsal venous arch. In the foot (for those whose arm veins are not good, or even missing) it's the great saphenous vein that you want to aim for. Any Google search for "veins of the (arm, hand, or foot)" will give you some good diagrams to locate them.