What is the simplest way to try a USB project? PyroElectro has a simple breadboard-based example of USB with a PIC microcontroller. It uses an interrupt driven HID USB device as an example, based on the Microchip USB stack.
Video below.
Via the contact form.
Here’s another intro guide to 18F usb on a breadboard: http://www.waitingforfriday.com/index.php/Building_a_PIC18F_USB_device
There’s another guide about configuring the framework here: Using the Microchip PIC18 USB CDC Framework