I have done quite a bit of resarch on this topic, and there are a few options.
My idea going in to researching what breweries do, is that if you as a homebrewer want to make beer like they do, then you should replicate the process they use. And it sorta makes sense that you can't make cold press coffee for 2-3000 liters of beer. It's just not feasible for most breweries.
I know that Hill Farmstead, Mikkeller and Stone and others grind the coffee fairly coarsely and put it in a fine mesh hop bag/sock and soak it in the fermenter a few days before packaging. Sometimes they add ground coffee directly without a hop bag, but then they filter the beer before packaging - quite roughly filtered though, just to get the coffee out of solution.
You need to be very careful about what coffee you use, and how long it soaks. Poor quality coffee imparts a real ashtray/sour tint to the finished beer.
However, be aware that some very high grade coffee is actually fairly sour as well when brewed correctly. Therefore it's a good idea to add some unfermentables to add some sweetness to balance it out.
Don't bother using whole beans. You need to grind them. It's sort of like making wort with malt that hasn't been milled. Yes you will get some slight amount of extraction, but nothing of any real value.
If you're not making your regular coffee with whole beans, then why would you in beer?
But that said, grind the beans yourself, never buy pre-ground coffee. And make sure it's as fresh as possible!
As for the amount, grind, brand, soak time etc. that's something you'll have to experiment with.