First things first, you're going to need to learn the basic stance. Stand with your feet shoulder-width apart, with your weight evenly distributed between both feet. Now, throw your hands up in the air and shout "I'M READY TO KNEES!"
This is the foundation upon which all other techniques are built. Without it, you'll be a slouchy mess of a fighter.
Next lesson: Knee Flicks 101
Or, if you're feeling adventurous: Knifen Tornado
Don't forget to manage your fear of being punched in the face
Now, get out there and start building those knee muscles!