LF a good guide explaining classes?

I'd Start MNK, (who knows..you might enjoy it) get it up to at least 18 minimum (probably higher if you want to solo farm the SJ items needed for quest), switch to War and use MNK as a SJ (boost is always nice to use for weaponskilling!) and take it to 30 (or higher to make obtaining SAM a bit easier). DRK is pretty easy to unlock...just takes time due to having to kill a certain amount of mobs with the "quest" item....which you want to keep by the way for a different quest for DRK that will give you an upgraded version of it =)