Your plugin sample_rasters was created in:
  /usr/share/qgis/python/plugins/sample_rasters

Your QGIS plugin directory is located at:
  /home/ruiz/.qgis2/python/plugins

What's Next

1. Copy the entire directory containing your new plugin to the QGIS plugin directory
2. Compile the ui file using pyuic4
3. Compile the resources file using pyrcc4
4. Test the plugin by enabling it in the QGIS plugin manager
5. Customize it by editing the implementation file sample_rasters.py
6. Create your own custom icon, replacing the default icon.png
7. Modify your user interface by opening sample_rasters.ui in Qt Designer (don't forget to compile it with pyuic4 after changing it)
8. You can use the Makefile to compile your Ui and resource files when you make changes. This requires GNU make (gmake)

For more information, see the PyQGIS Developer Cookbook at: http://www.qgis.org/pyqgis-cookbook/index.html.