One of my weakest skills is drawing. I have tried various approaches in the past but got easily discouraged.
Until now - I found Steven Aimone's book Expressive Drawing which approaches drawing quite differently. It's not about teaching realistic, representative drawing - this is about just playing, building a picture by making patterns, lines and shapes that please you. It's huge fun and suits my way of working very well.
Most importantly, I think, it gives you confidence in actually putting charcoal/pencil to paper because you're not trying to "do it right" - no one can look at this drawing, for example, and say "Well, that looks nothing like a cat with a gladiolus"