4 classes for a group of friends

[nostalgiaquest]

I'd advise against warrior or rogue as a first character. Only because (in my opinion) they're kind of boring classes unless geared out. If you have friends playing for the first time, you'll want to keep them excited. Warrior is just auto attack, kick, and taunt. Rogue is just auto attack and backstab. With paly/sk/monk, you have spells and abilities to look forward to getting to keep you interested.

I also say don't sleep on the bard! My favorite class by a long shot. A well played bard can really raise the quality of any group. But a shit played bard is worthless, so keep that in mind.