Well, as you can already tell you are gonna get a lot of opinions.. so here is mine.
Cold brew your coffee. Cold brewed coffee will have a lighter, more delicate flavor as the bitter oils are not extracted by this process. Avoiding these oils is important for head formation. Use a good coffee, not cheap store brand. Use a dark roast, Italian or espresso for example. Buy from a place that roasts their own coffee, and make sure you are buying beans that were roasted in the past couple days. Ask them to grind it extra coarse -french press or coarser (tell them you are cold-brewing). Use bottled water if your tap water isn't perfect - any off flavors will come thru in the coffee.
Cold brewing is easy. Put your coffee grounds in a container and add cold water. Use a lot of grounds, and a little water (last time I used 1/2lb espresso and 1 liter of water). Stir to make sure all the grounds get wet, and put it in the refrigerator for a couple days. You may have to stir occasionally to break up the crust on the top. When the coffee is done, the grounds will have sunk to the bottom. Decant your coffee through a filter (I put a cone filter in a funnel and pour it through).
If you are using a secondary, put the coffee in the secondary and rack the beer on top of it. If not using a secondary, pour the coffee into the bottling bucket with your priming sugar before racking your beer onto it.
