There are three basics you will need for using the heat embossing technique with your stamps...

1. A tacky stamp pad
   This is the ink that you will use to stamp your images before applying the embossing powder.  I recommend VersaMark as a good all-round stamp pad for heat embossing.
    
2. Embossing Powder
   Once you have stamped your image, you will add the embossing powder and then shake off any excess, so all that is left is what is stuck to your stamped image.  White, gold, and silver are three colours of embossing powder that are great to begin with.
    
3. Heat Tool
   The only thing left is to heat the embossing powder so it melts and sets.  For the best results, your heat tool should have good concentrated heat without a strong blow of air (don't use a hair dryer).  You won't regret investing in a purpose-built Heat Tool, but heating over a toaster is a good second-best, just don't burn your fingers!