Stefan,
Gawain comes from a Jose Silva background, so i like his stuff best. I did PhR her book, but decided that Belaruth's book is just as good & i already had that book.
So, if you don't have the Silva course or any Silva books. And, if you don't have a good book on visualization---then that's a good book to own for visualization stuff.
The key is to understand the difference between visualization and imagination. The more we practice visualization, the easier it is for our intuition to speak to us via our imagination.
There are all kinds of intuition books out there. If i'm not satisfied w/ where i'm at w/ my intuition development, then the next thing i'll be purchasing is the Intuition Tape Set from Sounds True. I forget that woman's name, but she's smart in that you just can't find her books easily to PhR 
Good Luck
