Watch the Quarter Notes online guitar lesson by Brad Carlton from Guitar Lab: Shuffle Secrets
This lesson starts with the basics: the quarter note. The quarter note corresponds with the tempo of whatever music you are playing. When you tap your foot, the moment your foot hits the ground represents the quarter notes. These are counted: 1 2 3 4.
You will receive a drum groove track which will establish this rhythmic concept. Spend time counting and playing along with the track so you are rock solid in your understanding of this rhythm.