hi José. There are no specific books dedicated to arranger keyboard playing techniques and concepts. I think THIS FORUM is probably the best place to come for this, and for Yamaha arrangers specifically, Joe Waters PSR Tutorial website: http://psrtutorial.com

In addition to the books José recommends, for jazz piano, I of course recommend the excellent and definitive 'Jazz Piano Book' by Mark Levine:
http://www.shermusic.com/jazzpno.htm

but maybe it's because I'm biased because he was once my piano teacher.

Perhaps even better than studying books, the best music teaching tool is listening to CDs and recordings of the music performed by the musicians we most admire, and then attempting to transcribe (notation or by ear) and play them on the piano, or on the arragner keyboard. It's amazing how much we can pick up with our ears. - Scott