I stumbled upon this YouTube video released by U.S Department of Homeland Security. If you are a first time visitor to America, you may want to watch this 2 minute video, if not you do not need to. It is very basic and just tells you in the form of animation video the US Port of entry procedures like filing an I-94 and US Customs forms when you enter USA and similarly what kind of Biometric procedures US Homeland security uses to protect legal international travelers’ identities. Also, what should you do when you exit or leave US.
Latest info at
http://www.dhs.gov/files/programs/editorial_0525.shtm