Where to Learn about Fourier transforms and Information Theory

I've been reading a lot of research papers this summer, and information theory and fourier transformation concepts have been coming up in a few interesting articles.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3139922/

http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1000239

I understand the gist of the concepts from a few youtube videos and wikipedia, but if I'm considering graduate school in this area I believe I need a deeper understanding. I'm an undergraduate student with two semesters of physics and calculus. Will the following books/classes be the most efficient way to learn about these concepts?

Spectral Analysis of Signals, Stoica & Moses: http://user.it.uu.se/~ps/SAS-new.pdf

https://ocw.mit.edu/resources/res-6-007-signals-and-systems-spring-2011/

http://videolectures.net/course_information_theory_pattern_recognition/

If not, what combination of classes and books will help me understand the concepts?