Welcome!
I have written three tutorials. All give programmers new to KDE and Qt application development a helping hand by showing how to develop an example full application step by step using KDevelop or QtCreator. I try to explain most lines of code and to give background information on how some of the design decisions are made.
As with most tutorials of this type, the pre-requisites are some knowledge of C++ and access to a system running KDE with KDevelop or QtCreator installed.
Please, if you do have any suggestions for improvements or spot any mistakes, please email me.
Hope you find these tutorials useful. Please check back in the future as I plan to extend them when I get the time.