Little question requires a big answer, but I will try to cut to the chase. Kenpo combines some of the circular movement found in Kung-Fu, Aikido, or Jui-Jitsu and combines them with the linear actions of Karate and Boxing. It was synthasized into a very structured, analytical striking system. It is probably more associated with hands than kicks, but by the time you include the sweeps, buckles, leg checks, maneuvers, scoops, hooks, etc - I think I work on a 50% hand & 50% legs.
A good video available commercially is "The Perfect Weapon" starring Jeff Speakman. He was a 4th Degree Black Belt at the time of the filming, and Blockbuster usually has it in stock, or can get it.
It is primarily a self-defense system that utilizes "techniques" which are usually more sophisticated than the "one-steps" block-strikes Tae-Kwon-Do teaches, or "katas" as practiced in Kendo. Our forms or katas, tend to be self-defense techniques strung together in a pattern against multiple attackers, combinations (e.g. jab-cross or kick-punch, etc.) We use Contact Manipulations as we enter into a close range combat situation. This includes joint locks or immobilizations, breaks, dislocations, pain compliance, and pressure points. Instead of "take downs" we tend to utilize strike downs in anticipation of the possibility of there being more than one attacker. I know Aikido also works with multiple opponents.
Weapons vary. In American Kenpo you always find staff, knife, double sticks (a little shorter usually than escrima sticks), nunchaku, sometimes spears and jo's.
Chinese Kenpo is a more circular version focusing on much larger circles looking more Kung-Fuey, includes chinese saber, spear, Quan-Do, etc. These forms and weapons are often "borrowed" from a traditional Kung-Fu system such as Hung-Gar or Choy-Li-Fut.
American Kenpo focuses on HOW YOU MOVE and smaller circles with a lot of whipping power. We focus on controlling all 3 Dimensions, height, width and depth. There are principles, concept, theories, and strategies that are well explicated and articulated. There is always an explanation as to "Why" you do something in American Kenpo and I really like that.
There is lots of information on the web regarding Kenpo. You can start by seeing my web page
kenpo-texas.com or go to goldendragon7's home page for more info, from there ... there are links to hundreds of web pages. You could spend a lifetime, and some people do, just answering your question of "What is Kenpo".
Thanks for checking out our forum. Enjoy your Art and training, we all do!
Michael B.
I very much respect all you guys on this thread who (I feel) love your kids enough to do what's best for them. 
Sounds like Kenpo is a good combination of everything a person should know to defend themselves!
Maybe I'm sheltered. 
