Standards
The USB specifications are now freely available from the USB-IF (implementers forum) at: http://www.usb.org/developers/docs/ and a copy of the most current at the time of going to press is included with this kit.
USB device classes specified here http://www.usb.org/developers/devclass/
Compliance testing specifications are also available from http://www.usb.org/developers/docs/ and http://www.usb.org/developers/compliance we’ll keep seeing this site referenced, it is the font of all USB knowledge.
Industry Associations
There really is only the one and it’s a good place to start further reading.
Certification
To use the USB Certified symbol on a product, that product must pass USB certification and this can be an expensive process. Compliance testing deals with electrical signal, power and software functionality.
Certification can be carried out at USB-IF Compliance Workshops, they’re free to USB-IF members. See the www.usb.org web site. At the time of writing, USB-IF membership costs $4000/year and a vendor ID (VID) will cost something like $1500 per 2 years.
Third party test houses are also able to assist getting products certified.
Testing can be an expensive time consuming process, to ease the burden most developers will resort to in-house pre-compliance testing. USB test patterns and scripts have been built in to oscilloscopes by the major vendors greatly simplifying the task.
Useful USB software test tools are available from http://www.usb.org/developers/tools/
USB product VID (Vendor ID) are only available from http://www.usb.org