I forgot to mention it but a couple days ago I finally found the last book I was missing for the Higher Learning achievement. It was the book in the Dalaran Visitors Center. I stopped in there looking for it I couldn't tell you how many times. I've found many other interesting books sitting there instead of the book I needed. I've been looking for this book for probably about 2 months now.
The weird thing is that popping into the Visitor Center is such a part of my Dalaran routine, I find myself still looking inside simply out of habit. It's sort of strange not to have to do that anymore.
The best news is that I am 9 pets away from Lil' Game Hunter. Pretty exciting!