Yeah, I know, but since the bookshelf doesn’t have some good/complete tutorials with great examples, I’ve used GitHub (it’s actually not only for issues). There is actually a lot of useful information/explanations about how things do work in bookshelf.
Also, check the bookshelf source files you find out that there everything is well commented and they provide examples directly in commentaries.
You will notice that more than 75% of its code are just explanations and examples for each function.