The standard wizards are still based on qmake, as QBS remains a "smaller brother" here ;)
Check out "the docs":http://qt-project.org/doc/qbs-1.2/index.html, they are generally getting better. The developers of QBS are very active and helpful on the QBS mailing list, too.
Also, there is a wiki "here":http://qt-project.org/wiki/QBS.