I used coffee beans in an amber ale, not a golden stout, so you might find this useful. I put 2.5oz whole bean medium roast plus 1.25oz of the same kind of beans but coarsely crushed like @Knightshade did), into a hop sack, threw it in a keg and racked over the coffee. After two days I pressure transferred to a serving keg. Way too much of a coffee flavor. It was more like a carbed up strong black iced coffee. The recipe did have 5.2% brown malt, and 3.4% amber malt, both of which normally give me a coffee flavor, so I'm quite sure they contributed to the coffee overload. My advice is don't do what I did!!
It's something a few breweries tried where they try to make a beer that tastes like a stout without using any roasted grains. It's essentially a stout grain bill with no roasted barley, chocolate malt, or patent malt, but with the roasted-like flavor coming from coffee and chocolate (usually cacao nibs). I remember Stone made one and there were a few other breweries that did as well (I'm sure they still make it, but it's been a while since I saw Stone's golden stout anywhere). I don't think it's that major of a "style" just yet, but it's been around for a few years now.
