"Kundalini" refers to the energy of the Root chakra, which surrounds the base of the spine.
The principle behind Kundalini yoga is that in freeing up this area, we can unleash the unlimited potential that lies within that energy center.
Expect lots of core work on your abs and around the spine with Kundalini yoga -- and perhaps even more sitting than usual.
If you want to begin your Kundalini yoga practice at home, we here at MBG recommend picking up the DVD, Kundalini for Beginners and Beyond, with Ana Brett and Ravi Singh. It's a great DVD to get you started with the basics.