Not sure what type of place you work or if this idea would be appropriate. However, have you thought of going to your boss and saying something like this:
"I really like my job here and I want to make sure I am meeting all of your expectations. I had a chance to think about the feedback you gave me during my performance review. Improving my comunication skills is important to me and it is absolutely something I want to work on.
I do struggle sometimes to understand specifically what I can do to improve in this area. I would like to find a mentor who would take the time to coach me. What do you think about that idea? Is there someone here who you would suggest I ask for assistance?"
I'm not sure a book can help you as much as someone who actually sees how you interact with others and can give you specific suggestions.
Cheers.