There are lots of examples wich U can find in most of power semiconductor manufacturers, but have a look to this
www.powerint.com and there you will find AN´s Engenieering reports wich also include PCB and the designer software PI Expert.
www.onsemi.com more info and download POWER 1-2-3 design and simulation tool
www.ti.com and look for SMPS seminars and app. notes.
Hope this help U