Today's bows are not "pieces of junk". Some are just made better than others...
There are tons of websites dedicated to archery, bowhunting, bow terminology, etc...
I would first start at looking through "Hunters Friend" and read their articles. They have a great site and great bow selections!
http://www.huntersfriend.com
Here is the direct link to everything you want to know about compound bows:
http://www.huntersfriend.com/bowselection.htm