Good timing, I brewed my first Coffee Stout a month or so ago and have been drinking it away. I followed a friend's procedure and it turned out great:
6oz coffee beans
- Rough crush them with rolling pin/mallet whatever you have
Sanitize rubbermaid food container that will be able to hold the beans plus 48oz of sterilized water (just boiled it and then cooled it down)
Take the crush beans and put them into the container, pour the 48oz of water ontop of them and put the container in the fridge for 2-3 days.
After 3 days, using a strainer and coffee filter I drained this mixture into a bottling bucket then dumped in my priming sugar solution.
Rack beer ontop of all which will mix everything nicely. I will say this does have extreme coffee flavor which I love, if you want it less cut the coffee addition in half.