This chapter is only for those who enjoyed this tutorial and want to know more about the UNO component creation in Java or other languages. You will have a list of useful links for any UNO developer in the next line.
OpenOffice.org developer's guide is still a huge source of documentation for LibreOffice extensions developers. You should probably have a look at the chapters 3, 4 and 5 for UNO components informations.
LibreOffice Java reference is the UNO binding for Java reference.
UNO API reference will provide you the documentation for the LibreOffice UNO API.