I don't have links, but I have some advice that may be contrary to what a CS major might say. I recommend against a CS-first approach. Focus on theoretical fundamentals. Take "DFT" and "FFT" out of your lexicon -- those are not important right now. Forget about the the D and the P in DSP. Focus on the S: signals. Signals are just waves. Understand the mathematical basics of waves -- bonus points if you study differential equations whose solutions are waves.

Once you're pretty confident with your understanding of wave math, next focus on linear algebra. Linear algebra sounds like a strange requirement for understanding signals, but it actually is fundamental. Fourier series should then just "click" for you -- a Fourier transform is basically a change of basis in a vector space.

Bonus points if you learn about infinite-dimensional vector spaces, what Dirac delta functions are and what they mean. For example, why is it that a delta function has infinite spectral energy? Either you have no idea, or you find the answer obvious. There is no in between. Good DSP folks can answer theoretical questions like this without thinking. Once you understand how to think about waves in the time basis and the frequency basis, you will be well equipped to understand pretty much everything in DSP.