i like to heal people but also dish out some damage i would be straight holy

well generally if ur straight holy, you arent gonna be the one fighting. you will be a healer and maybe help out the dpsers on occasion.

This all depends on if your in an instance or just mob grinding in a party. If you in an instance, your going to want to let your party members do DPS while you heal them. If your out mob grinding, your party members should each take on one mob and have your DPS come help you when their done and heal after wards.

In terms of gear, once you get to outlands theres a lot of quest items that give some nice holy pally gear. If your gonna buy greens from the AH, I'd suggest getting about 2/3rds of your gear of the Sorcerer, and 1/3rd of the Invoker. No strength or agility is really needed as a holy pally if you know which seals to release and use.

Best way for a holy pally to DPS solo is to seal release Seal of the Crusader, then use Seal of Righteousness. If their demons dont forget to use Exorcism. If your in nearly all Sorcerer and Invoker gear, you should be able to hit 700-800 Holy Shock, Exocism, SoR releases, and hammer of wrath's.

Atm, my SoR (Seal of Righteousness) hits 200 per melee hit with a 2.00 speed weapon as a lvl 61, which is about 8x what the default text for the spell says :P