where is Qt and qmake installed

[spirit]

Well, if you use QtCreator from QtSDK then you don't need to do anything. QtCreator will find qmake by itself. But if you need to add additional Qt version then you should go to QtCreator's preferences (cmd + ,), navigate to "Build & Run", select "Qt Versions" tab. Here you can simply add any new versions.

If you need to use qmake in the console then you have to export path to the qmake into PATH system variable like this:

export QTDIR=<path_to_qt_folder>
export PATH=$QTDIR/bin:$PATH

After that you can simply use qmake in any project's folder to build it.

Optionally: You'd also, probably, need to install XCode's command line tools to use make and other comman-line tools, but it's only for XCode 4.3 and higher.