Hi,
Lock Pick skill is something I did not level up max in the beginning. For sure now I play on "high" I feel need of other skills in battle.
There are enough hidden treasures to find and loot ... with gear, weapons etc in ...
The first time I played I maxing Lock Pick and found sometimes equipment I can't wear because I wasn't a high enough level or haven't the Strength or Dexerity to wear it yet! So I decised now to wait with max out my Lock Pick.
Now on level 14 I have 2 (or 3, can be, not sure) points in Lock Pick!
If a chest or whatever can't open via Lock Pick, there must somewhere a KEY to find or a quest to trigger ...
(with Lock Pick 5/5 : only a few chests I didn't find a key for and can't open with Lock Pick ... )
Some books are Quest-items, but in that case, you find them by your questitems-log in your Inventory. All other books are for telling some history or some funny stories
...