Respostas:
Você pode adicionar ícones à barra de ferramentas ou menus. Para mais informações, consulte o pyqgis Cookbook http://www.qgis.org/pyqgis-cookbook/plugins.html
def initGui(self):
# create action that will start plugin configuration
self.action = QAction(QIcon(":/plugins/testplug/icon.png"), "Test plugin", self.iface.mainWindow())
self.action.setWhatsThis("Configuration for test plugin")
self.action.setStatusTip("This is status tip")
QObject.connect(self.action, SIGNAL("triggered()"), self.run)
# add toolbar button and menu item
self.iface.addToolBarIcon(self.action)
self.iface.addPluginToMenu("&Test plugins", self.action)