[oe] selecting needed applications only

[mahmut g]

I am new at OE. Actually I heard from many people Openembedded is the best and decided to try. However I couldn't figure out how I can select applications just I want to be included to my image. There are too many files and rules. I had tired to use with beagle board and finally given up. The main reason for learning and using OE was that we wanted to use QT on our board. May someone advice any nice guide or documents which show how to select just wanted applications and how I can add a new application, it will be appreciated. 
Regards,
MahmutG