How to study Nuxeo Java Client API?

Hi,
I would like to build a sample Nuxeo client app (against EJB remoting or HTTP Client API) with primitive
implementations of document search, download/upload, extract metadata, etc 

I have got familiar with Nuxeo book where I found lots of architecture, deployment and administration
chapters. 

Nevertheless, I did not find any chapters about Java Client API overview. I decided to go forward and
checked out code from SVN - http://svn.nuxeo.org/nuxeo and found some samples in /sandbox directory but
it didn't give a good picrure of API.

Could you please advise me documentation resources or something like best dev practices on that?

Thanks.