Recommended Reading

Topology and the Language of Mathematics by Chris Cunliffe
The Art of Problem Solving by Sandor Lehoczky and Richard Rusczyk
How to Solve It by G. Polya
The Art and Craft of Problem Solving by Paul Zeitz
Geometry Revisited by H. Coxeter and S. Greitzer
What is Mathematics? by R.Courant, H. Robbins, I. Stewart
Godel, Escher, Bach by Douglas Hofstadter
Godel's Proof by Ernest Nagel and James R. Newman
Godel, Escher, Bach: An Eternal Golden Braid by Douglas R. Hofstadter
Journey into Geometries by Marta Sved
Problems for Mathematicians, Young and Old by Paul Halmos
Mathematical Tourist by I. Peterson
Archimedes' Revenge by Paul Hoffman
Mathematical Carnival by Martin Gardner
In Code: A mathematical journey by Sarah Flannery
The Code Book by Simon Singh
The Man Who Loved Only Numbers by Paul Hoffman
Fermat's Enigma by Simon Singh
Crypto by Steven Levy
Journey Through Genius by William Dunham
History of Mathematics by Boyer
The Nothing That Is: A Natural History of Zero by Robert Kaplan
The Golden Ratio: The story of phi, the world's most astonishing number by Mario Livio
Mathematician's Apology by G. H. Hardy
Flatland by E. Abbot
Flatterland by I. Stewart
Innumeracy by John Allen Paulos
Proofs Without Words and Proofs Without Words, Vol 2 by R. Nelsen
Mathematical Cranks by Underwood Dudley