User Experience Designers, as opposed to people who program user interfaces, are a whole class of professionals in their own right. They may or may not be programmers.

If you really want to get into the business properly you will probably need to get additional training if you want to get into this field as a full-time professional- a Master's degree is most likely the minimum requirement. Lots have PhDs. If you think this is unnecessarily strict, imagine how you would feel if someone with a degree in User Interface Design thought they were qualified to code that interface because they had read one book on programming.

Having said that, if you want to be a programmer with a high degree of interest in user interfaces, there are plenty of books that will teach you about this.