The best one is the National UFO Reporting Center.

There are roughly 600-700 reported sightings annually.

There is no reliable data on the number of UFO sightings reported specifically in AD 960 as modern methods of tracking and documenting UFO sightings did not exist at that time. UFO reports began to be documented in the mid-20th century with the establishment of organizations like the Mutual UFO Network (MUFON) and the National UFO Reporting Center (NUFORC).

There are many around the world, these are American:MUFON (Mutual UFO Network) founded in 1969, NUFORC (J. Allen Hynek Center for UFO Reporting Center) founded 1974 and CUFOS (J. Allen Hynek Center for UFO Studies) founded in 1973.

There are several different places where one can find UFO videos. Most UFO videos can be found on video sharing sites such as YouTube, but they can also be found on social networking sites (such as Twitter and Tumblr) by searching the hashtag "UFO".