the road to learning useful math
johnmyleswhite: It sounds like you're interested in statistics from the words "a few interesting stats-heavy compsci papers". The MacKay book, "Information Theory, Inference and Learning Algorithms," already referenced by benm is quite good, but I'd suggest on top of it Larry Wasserman's amazing book, "All of Statistics". If the level of calculus and linear calculus in that book is too much for you, you might need to review that material first before moving on to anything sophisticated in statistics.In the interim, you could start with David Freedman's "Statistics" (written along with Pisani and Purves) to at least get a feel for the basic ideas of statistics from one of the great statistical writers of the 20th century.If there are other things you want to learn about, I'd be happy to make suggestions, as I went in the opposite direction as you're trying to go now, having been a math major as an undergrad who picked up CS along the way. For cryptography, for instance, you'd need to learn number theory and then abstract algebra, but those things will be of little use to you in other contexts.