Bulk priming is fairly simple. It is adding the priming sugar, dissolved in boiled water, to the bottling bucket. A calculator comes in handy. This is a good one, lists all the different types of sugars that can be used. Corn sugar and table sugar are the most commonly used. Easy to dissolve and form carbonation in less time than other sugars. Table sugar is also usually on hand and cheap.
http://www.northernbrewer.com/priming-sugar-calculator/
Enter your numbers at the top, look for the weight of sugar to use for the carbonation level chosen. Weighing the priming sugar is much more accurate than trying to use a volume measure.
Temperature is the temperature the beer was held at after fermentation. Cold beer in a bucket or carboy will hold more CO2 in suspension than a warm beer, therefore a cold beer will need less priming sugar. Holding your beer for three weeks will allow almost all of the CO2 to dissipate. I usually just enter 68°F.
My procedure is:
Start the auto siphon, when one-third of the beer is in the bottling bucket, slowly add the priming solution. No splashing.
The siphon action will swirl the beer in the bucket, curled siphon tube laying on the bottom does this, to mix the priming solution with the beer.
As further insurance I will use a sanitized spoon to gently stir, no splashing or vortex, the beer to make sure the priming solution is evenly mixed.
Proceed to bottling.
My preferences:
2.0, or less, volumes of CO2 is fairly flat
2.2 to 2.4 stouts to amber ales
2.6 to 2.8 petite French saison, spritzy
2.8 to 3.0 Bavarian hefeweizen, highly carbed.
