Concise client side JPA tutorials

Concise client side JPA tutorials

I have always managed to find concise and ultra easy to understand
tutorials for most aspects of Java, but now that I am trying to look for a
good tutorial on using JPA I can't seem to find anything even vaguely
legible (at least not to my limited understanding). I think perhaps I may
have some kind of misunderstanding that is preventing me from finding what
I need. So, once again, I ask the gifted coders of Stackoverflow for
advice.
Q; Where can I find concise, easy to understand, JPA basics tutorials?
Background; I am creating management software for my employer and have
decided to use JPA so that I can create objects that relate to entries in
their SQL database to manipulate those, rather than sending hundreds of
queries back and forth to their server.