This article discusses about difference between Information Architecture (it is a structure) and User Experience (it is emotion): http://www.uxbooth.com/articles/the-difference-between-ia-and-ux-design/

This article briefly introduce Information Architecture: http://www.usability.gov/what-and-why/information-architecture.html and also this is a nice prezi’s intro on IA   https://prezi.com/aafmvya6bk7t/understanding-information-architecture/

References:

 

• The Elements of User Experience: User-Centered Design for the Web and Beyond (2nd Edition) by Jesse James Garrett
• Information Architecture for the World Wide Web: Designing Large-Scale Web Sites by Peter Morville and Louis Rosenfeld