Is there a book or a website someone could point me to that has a great explanation of his? For example, something that explains why a hop is an aroma hop, or why I care about alpha and beta acids.
I haven't gotten this one yet but I do have a couple of the other books in the series (Water and Yeast). They get pretty detailed and into the weeds with the subject matter.
That book would probably be a good place to start, but there's always new research being done. I just happened to see this the other day:
Myth No. 3: Only flavour hops are suitable for dry-hopping. High alpha varieties are unsuitable for dry-hopping.
Wrong again! Basically, any variety is suitable for dry-hopping. Regardless of whether its a high alpha variety or a fine aroma variety, each one has its unmistakable aroma profile and thus contributes to the aroma of the beer. It always depends on how the variety is used. In other words: not every hop variety suits every type of beer, and adding a lot of hops doesnt always produce a beer with the best of aromas. What is incredibly exciting is to tease the very best out of each hop variety and then to discover that some hop varieties can be an excellent complement to the traditional beer styles in particular.