There's a separate page for my best-seller How to Think Like a Mathematician.
I'm finishing a book on Complex Analysis for undergraduates. In the meantime, I've put a short proof of Cauchy's Theorem on my blog.
Variational Problems in Differential Geometry - Leeds 2009, ed. Roger Bielawski, Kevin Houston, Martin Speight was published in 2011 by Cambridge University Press 2011.
This is the Proceedings of a conference we held in Leeds. You can buy it from the publishers and all good bookshops.
The Proceedings of São Carlos Real and Complex Singularities 2010, ed. Victor Goryunov, Kevin Houston, Roberta Wik Atique was published by the American Mathematical Society in 2012. You can buy it from them here.