Healer's aren't required to DPS - but the best healers will know when they can DPS and when they need to heal.

Your first goal is to learn how to heal efficiently. Once you have that, then you can begin learning how to weave your DPS into your healing thought process.

Good luck

Also:

Quote Originally Posted by Astral145 View Post
Make a raise macro that says

/micon
ac/ "swiftcast" <me>
p/ "well you told me to dps so I did, don't blame me for why you are making love to the ground."
/wait 1
/ac "Resurrection" <t>
p/ "Now get up and stop complaining"
Please don't do this. This is just as rude and ignorant as the players getting mad at you for not DPSing on a healer. Just tell them "no" and move on. If they kick you for it, you didn't want to play with them anyway.