Watch the Alternate Guide online guitar lesson by Brad Carlton from Chord Studies: Evolving Progressions Vol. 1
This is a four bar progression in the key of E and it is using the I - iii -ii -V form. This is a great progression to try out some alternate fingerings. For instance, if you were to finger the E chord with your second, third and fourth fingers then your third and fourth fingers would become guide fingers leading into the iii chord, G♯m.