Watch the Pentatonic online guitar lesson by Brad Carlton from Guitar Lab: Super Sustain
In this lesson we will use a pentatonic approach to soloing over these four chords in the key of C. Diagrams 2a through 2d show the pentatonic scales for each of these chords in the fifth position. We are using the following approach in choosing our pentatonic scales: major pentatonic over a major chord, and minor pentatonic over a minor chord. I suggest that you start by just viewing the information on the first and second strings. This way you will see what common tones exist between each pentatonic scale and you'll also see what notes change. Then as you become comfortable with two strings, add another string and so on. Remember you must think ahead to the upcoming chord and view the pentatonic scale so you're ready to change exactly when the chord changes. This is the opposite to what you may be accustomed to if you played a lot of blues or rock where you just stayed in one pentatonic scale. That approach to soloing is called horizontal soloing.
After you get a handle on changing pentatonic scales with each chord in fifth position, try plotting out the remaining four positions on the fingerboard. You can use your master diagram of the C major scale to access this information. Obviously this means you have to know the names of the notes that you're playing with each scale so don't avoid this discipline.