Rule #5 -- Quest help
Don't walk people through quests. One small hint ought to be enough to help someone on their way. The quests are there for people to solve, not for you to solve them for others.
Helping people with difficult kills or in cases where there is a "physical" need for two characters (as in Killroy's quest) is okay, but don't overdo it. Ask a QC Arch if you're in doubt whether the quest in question is made for several players or not.