You'll want to use a double boiler to melt chocolate on the stove. To do this, first make sure you have a pot and heatproof bowl that fit together properly. The bowl should fit snugly over the pot (so no steam escapes) and the bottom should rest without touching the bottom of the pot. Then, you'll want to add about an inch of water to your pot and bring it to a simmer. Place your bowl of chocolate directly over the pot of simmering water (it shouldn't be touching the water) and stir constantly as it melts. I tend to prefer the microwave method over the stovetop method, since a double boiler introduces water. A tiny splatter or even steam can still cause your chocolate to seize.