menloparkbum

Concrete Mathematics by Knuth, Graham, Patashnik

while it's a cool book, speaking as a former math tutor, it isn't the most helpful from a self study perspective.

Calculus Made Easy by Silvanius P. Thompson

The Schuam's outlines in each topic are good for review.

Fundamentals of Applied Probability Theory by Alvin Drake

I like James R. Newman's "The World of Mathematics."