I own the book filled with hints, otherwise I would not even know I should ask this question. Doing the series of quests for the Temple of Kynareth of White Run, I have activated the Eldergleam tree and have walked down the path in search of the mentioned skill book that is written of in the hint book. There are two waterfalls, each near the path at different twists and the skill book is supposed to be tucked against some rocks near the path that is close to the waterfall. However, I surely must not be looking in the right locations. Any tips of where to look?

According to the uesp, the book is leaning on a rock near the NPC's "Asta"s backpack. So in the middle.

http://www.uesp.net/wiki/Skyrim:Eldergleam_Sanctuary

Also, this isn't anything major, but the quest is just that, a quest. Not a series of quests. That would've been interesting though.

I'd trust the UESP wiki before I'd trust the first edition strategy guide if that is the book of hints you are talking about. Lots of errors in that guide. Don't know if they corrected them in the legendary edition. I don't own that one.