Singing Lessons - Learning?

I am not the poorest, but not the richest either. I would love to learn how to sing and of course become a professional recording artist, although I cannot afford singing lessons. Youtube videos with separate techniques for singing high notes and others do not really help me. I live in a city near London so maybe someone knows any teachers that could help me. If it depends on something, I would like to be type of singer as J.Timberlake, Ne-Yo or Usher be. Thank You!