As arterra and noneo have said generally sticking to your main stat having said that im a lvl 50 bear and have mainly increased my str and dex. I like being strong - high hp and armour but also do dmg so have higher hit rate and dps increasing my dex.your probably already know but -
More str = higher hp and armour capabilities and physical dmg.
More dex = higher hit success rate and can increase your overall dps(damage per second).
More int = more mana to use on special abilities i.e magic and also do more magic dmg.as noneo said paladin is a good way to go.ive just started on a lvl 7 currently mage and am working toward a pally too. Please correct me folks if i gave wrong info on what increasing certain stats do.