I learned quite a bit of new information on various calibers, history, terminology, and many of the "why's" I did not know before when I took up handloading- most of the reloading manuals do a great job of this. You can pick them up for very little:
http://www.amazon.com/gp/offer-listi...condition=used
Also, I like this one for rifles:
http://www.amazon.com/gp/offer-listi...condition=used