1)I want to know about the paths to use hibernate session to save, update, delete objects,

with transactions opening and closing,

the extremely suffering way.

I used to run into a book 3 years ago but can not remember its name.
Is there such a book you can advise?

2)How can a javax.persistence.entityManager do things more simple and light and error-free(imho) way than org.hibernate.session,

should i look into the code of these classes to understand?

THanks

There is a banner on the top of this page, those two are the best ones you can find I think.