Before compiling, please see iqnotes.pro. Pay attention to this lines:

CONFIG = qt warn_on desktop
This should be written if you are going to compile desktop version.  

DEFINES = IQNOTES_PICDIR="\"/usr/share/iqnotes\""
That defines the directory for the pictures which can be assigned to the note.

To compile IQNotes, please write at source directory:

qmake -o Makefile iqnotes.pro
make

Binary file is located at ../bin. Then please create directory defined by
IQNOTES_PICDIR macro and copy there a content of the pics/ directory.
And that's all folks!