Watch the Close Voicings: online guitar lesson by Brad Carlton from Guitar Lab: The Golden Arp
Close voiced add 9 chords in 2nd inversion are covered in this lesson. These voicings are quite practical and can be played with the fretting hand without extreme contortion. The 3rd will be the lowest voice in these chords so one way to view them on the fingerboard is to take 1st inversion major triads and place the 9 on top as the 1st voice. I will show you various fingerings for the voicing on the middle four strings.