Well... i never did weed chocolate, but i did hash oil chocolate, and the results were always excellent!

http://boards.cannabis.com/recipes/1...very-easy.html

But you could try with weed, and see if you get good results. I would suggest you to follow the advice of Zwitter, toast you weed and grind it after. Of course you can heat the weed in the microwave, but toasting makes it easier to grind to a fine powder (the finest you can).
Just remember to use the right temperature for doing so, for avoid losing THC. Look it at the green dragon recipe:

http://boards.cannabis.com/recipes/8...-combined.html

After mix it very well with the molten chocolate, put it into the freezer (or the coldest place you get). As colder the place, as harder the chocolate will became. I think thats what Zwitter calls "tempering" the chocolate.