When I've made coffee beers, I've always steeped the coffee grounds in the wort just after I kill the heat. Coffee connoisseurs will tell you that "a coffee boiled is a coffee spoiled..." so I wouldn't add the grounds to the boil. I would imagine that you could brew the coffee beforehand and add that to the secondary, but I don't have experience with that. I've had good results with just putting the grounds in a hop sock and dropping it in the wort after the boil ends and let it steep for several minutes.
As far as the chocolate, I would add it to the boil within the last 5-10 minutes. I've only used cocoa powder and never chocolate itself, but I imagine it's the same principle.
1. ESB 2. Citrus Wheat 3. Czech Pils 4. Ger Pils 5.[Nitrogen] Dry Stout
1. MI IPL 2. MI IPL 3. Saison 4. Saison 5. Porter 6. Porter
1. Brett Ale 2. Lambic 3. Lambic 4. none 5. none
About 18 gallons of beer & 3 gallons of mead
Kegged & conditioning:
Bock x2, ESB, IPA, Ger Pils, Czech Pils