Hey, does anyone recommend any?

I am currently entering my second year of Further Maths pre-uni and I recently bought a book that looked promising called 'The Art and Craft of Problem Solving' by Paul Zeitz.

I'm mainly trying to work on my ability to problem solve. Trying to work out certain proofs etc which I am sure will help for University. In College all we do really is a tiny little work on Proofs and my main problem with learning Maths pre-Uni is you learn to answer everything in a very systematic manner. You never truly "answer" a question you simply remember the process in which you obtain said answer.

Anyway, enough blabbing. Anyone know any good books?