RFID is one of many forms of identification or AIDC and as such also one of many PEID technologies. 

People working on this site already know what RFID is.

There is a huge amount of information available on RFID and it is not intended to repeat it here.

What we need here is links to the best sources to specialised sites and materials. To find it all in one place.

The RFID Journal is one of the most well known sources for starters, but there are more specialised forums and places that deserve a mention.