A slashing/crushing combo is what I did for most of the first act (where there were lots of skeletons around). Once I reached the citadel, I switched my hero to being an archer full time (two warriors is also a viable strategy). Playing again I'd have my DK be a bow archer, to concentrate on agility.
The act 1 summoning doll (available on the second level, after you jump down the pit in the arena) can equip a crossbow, and kept out of harms way (melee combat) could provide good support. I only used it a couple times, for tough fights, but it did come in handy.
The DK doesn't need strength for armour requirements, so depending on weapon requirements, may be able to devote a little more to intelligence (Shaman magic is the way to go; you may find Hammer to be a better targeted spell than Fireball, but I never played a mage, so that is mostly speculation based on stuff I kind of remember reading).
The math appendix in the
Beyond Divinity Strategy Guide has some general comments on stat point distribution. There are many viable builds, so you kind of have to adjust things as you go, based on the equipment you find, your playstyle, etc.
