I have made several brews with coffee additions... I like to add mine on the post fermentation side of things.... Get 2oz of coarsely ground coffee, your favorite variety will work. I like Seattle style since it is so robust. Cold steep it in 12-16oz of water for 24hrs. Strain out the grounds, and if you are worried about sanitation boil the coffee toddy you made before you add it to the keg or bottling bucket. You can add coffee to the boil, or steep it like grains but it is much harder to control the amount of flavor you will get. If you boil or steep too long you will get some astringency from the coffee.