Human Interface Devices (HID) Links and Businesses
(Products, services and websites vary with time. Please verify.)

Google Weblinks Security Check

Bluetooth HID
Jan Alexson Lakeview Research
Microsoft Related HID Documentation - The USB-IF's collection of Microsoft's HID documentation.
USB-IF HID Tools - The USB-IF's page devoted to human interface devices. Includes all approved documentation.

Various Related:

An Analysis of Wireless Device Implementations on USB (PDf file)
The last HID 1.11 Specification (PDF file)
Serial HID
USB Human Interface Device
Wikipedia Definition