Here's another reference tool I thought I'd share with everyone here on SR. This is a chart showing different ways that you can modulate (change key) in your song. It shows the original key, the key that you want to move to, and the "transition" or "pivot" chord(s) you could use to move you into the new key. Hope you find this useful!
John Westwood
Saves me from working out the transitional chords by ear Wot ears ? you may well ask