I recently tried tempering chocolate when I enrobed my truffles this past Christmas. I am in no way an expert, far from it. But here's the way I did it:
1) Heat 2/3 of your chocolate over a double boiler (I used a heat proof bowl over a pan of water) to 115 F (dark choc)
and 110 F ( milk choc).
2) Take your bowl off the heat and start to put the remaining 1/3 chopped chocolate into the melted chocolate bit by bit to bring the temp down to 82 F (dark)
and 80 F (milk)
3) Put your bowl back over the double boiler and bring the temp back up to 88-90 F (dark)
and 86-88 F (milk).
Keep your eye on this and I take it off the double boiler just short of the target temp as the chocolate will still increase in temperature.Some notes:
I have also seen this done where you skip step 2, add the 1/3 of your chocolate and drop the temp to 90 F (dark) and keep it there. I've never tried it, but the pictures I've seen look like they are in temper.
I have, and still struggle with keeping my chocolate in temper. One way that seemed to help this was to put foil on an electric pad and put my bowl on that. My metal bowl worked better than my glass bowl. Be careful though, heating pads can vary in heat intensity, so keep an eye on your temp.
If you see that your chocolate is out of temper (dull finish, or streaky) you will need to go through the tempering process again. This is as much an art as it is a science, so if things don't seem to work out, don't get discouraged. I'm still struggling with it.
Hope that helped and sorry if I talked too much.