Below are chord fingering diagrams for a selection of useful chords with the root of C. Blue circles indicate fingers on the right hand, but left hand fingers could also be used for some or all of the notes. It is very important to note that on the harpejji, once you a learn a chord type fingering for one root, like C, the same fingering applies to all roots. You just shift the pattern left, right, up or down so that the new root replaces the C.