I always use a double boiler. Chocolate is tricky. You must go slowly: If you allow the chocolate to get too hot, it'll look "dry", you're done -- that chocolate is ruined. You can go from "almost there" to "ruined" in seconds; I said, it's tricky. The microwave is bad for burning.
If I'm using chocolate chips (or similar), I add wax or a bit of vegetable oil. Again, go slowly: Add a bit, stir and wait, add a bit, stir and wait. You can always add one more drop, but you can't take a drop out. Don't worry about eating wax: If you eat commercial candy, you eat wax.
The Wilton wafers sold at AC Moore (and similar) are easier than real chocolate, but they're not as tasty. They have chocolate flavor, peanut butter flavor, and vanilla flavor (in multiple colors). These are GREAT for a beginner.
Pretzel rods are, in my opinion, the easiest because you've got a built-in handle. If you're using smaller items, look for the Wilton dipper set (less than $5 in the cake decorating section of craft stores). Three pieces of plastic designed for dipping -- better than the fork I used to use.
Finally, if you're having trouble getting things to stick . . . you need to add the wax or vegetable oil to make your chocolate "softer", and you need to go straight from the chocolate to the enhancement item -- you have to move fast to do this type of work! I like to put my sprinkles, chopped nuts, etc. on waxed paper, which allows me to lift the edges and bring everything together in the middle -- and allows me to press the good stuff onto the wet chocolate.