I hate helping low levels. BUT...
You do have to think. You were ONCE a low-level, so you should help them out a bit.
But don't hold-their-hand thru the whole entire game. Only EVER help with group quests if they have not tried general chat. and ONLY EVER run instances when they have quests for it. So they get more XP. And you level them quicker thus needing to help them less because they will get to max level quicker!