This is the basic user manual. Here, you'll find the information you need to use the everyday functions of your machine, along with explanations of the various ports, controls and special function keys. This is a good resource even if you're simply doing pre-purchase research to decide whether the Yoga 2 Pro is the right machine for you.
This is an in-depth hardware manual for the machine. Within it, you'll find details ranging from error codes, to BIOS settings, tear-down and reassembly instructions and the FRU parts listing. Considering that most everything except the power adapter is listed as a FRU - field replaceable unit (vs CRU - customer replaceable unit), one should approach the material contained within with care. Regardless, there is a wealth of detailed information about the Yoga 2 Pro present in this document.
This is the definitive place to find new / updated hardware drivers and software utilities applicable to the Yoga 2 Pro as the become available and are released by Lenovo. Whether you're seeking video or audio drivers, or a BIOS update, if it's been made availbale, this is the place to find it. The driver matrix is very much worth checking regularly.