For mathematical practice I consider the best

Mathematica®: A Problem-Centered Approach - Robert A. Hazrat,

or a bit older

Mathematica® in Action - Stan Wagon

For invent procedures or solutions

Programming with Mathematica: An Introduction - Paul Wellin

and for for practical applications such as working with - for example - biological data

Mathematica Beyond Mathematics: José Guillermo Sánchez León

Unfortunately, I still lack any practical textbook, which works with news from version 10 up (e.q. Dataset, some news plots & graphics, Machine learning, 3D geometry, cloud(!)...)