Good move! Power chords are very limiting. If all you ever want to play is heavy metal they will work, but other styles will sound weak with them. When I made the transition from power chords to "real chords", I used Blues as training. The minor 7th rules the blues, along with 9ths and a few others. But its not too overwhelming. The I-IV-V progressions are a lot more easier to work with too.
Anyway, I would say let your musical interests reflect the chords you use. If you just want to learn other chords for fun or whatever, I would suggest starting with open chords, then move on to the barre chords(I had a hard time with barre chords). Enough practice, and before you know it your hand will go to make a full chord, where it normally jumped on a power chord. Good luck!