How to start with USB device driver.

Hello all I have basic knowledge of character device driver, I would like to learn writing a simple character driver for USB because on my laptop only I can communicate with usb I don't have any Boards. Can anyone suggest some tutorials or simple project to learn USB device driver ? And suggest me any hardware for other side also. Now I am planning to use my PIC board (it has usb) to communicate with linux. Thanks in advance. Sent from my HTC