Watch the Percussive Groove online guitar lesson by Daniel Champagne from Essentials: Percussive Fingerstyle
We are looking at three different percussive sounds here...
1) A kick drum made with your palm on the face above the sound hole.
2) A snare sound made with you open hand on the bottom side of the guitar.
3) A hi-hat slap with the left hand against your strings while muted
Count yourself in, start out slowly and build it up. Never hit it too hard because guitars DO break.