Depending on what you want, there are some reference books that I found very good:
Switchmode power supply handbook, by Kieth Billings
Switching power supply design, by Abraham Pressman
Switch-mode power supplies; SPICE simulations and practical designs, by Christoph Basso
Each covers different aspects of the supply, with the handbook being more about the small, often forgotten details like inrush limiting, auxilliary power, and transistor drive circuits. The SPICE book is obviously skewed more towards getting a supply simulating and the design aspects.
Of course, no book is likely to ever deal directly with the application you're trying to design for!