Don't be too worried about a rotation until you're 70. You'll be gaining too many new things. Like Hasrat said keep up your dots and your songs. Now the only thing I don't know is if bard songs stack or not, but I'm guessing if it's not foes then like anything else that isn't a regen two bards cant be playing songs at the same time. Also don't forget to aoe stuff when they're in 3+ packs. Your tank and healer will love you.