I’ll place links and resources here that I find useful.
Mathematics for Computer Science
The free text Mathematics for Computer Science by Eric Lehman and Tom Leighton is a great text for mathematics that I think many people today, not just programmers, will find very applicable for problem solving in their everyday lives.
The textbook “Matters Computational” (formerly titled “Algorithms for Programmers”) by Jörg Arndt sells for $199 on Amazon, but in agreement with the publisher can be downloaded for free at this site. This is simply an amazing text.
There are several well-known and standard texts for learning algorithms. “Data Structures and Algorithms” by K. Mehlhorn and P. Sanders is one of them, and can be downloaded for free from one of the author’s websites here.
Another good text is “Algorithms” by S. Dasgupta, C.H. Papadimitriou, and U.V. Vazirani. The penultimate draft if the text is available for free online here.