Most of the info for D2:ED is similar in DKS, but there are notable differences. Equipment stat requirements were removed in DKS, which allows greater flexibility in mixing classes or changing builds late in the game. Several skills were changed so they are not as effective (like Bleed) or not overpowered (Explosive Arrows). Most significantly, magic damage enchantments were changed so that the bonus of each weapon is applied to both, as well as to spells (the duel wield skill is not required for mages, as the off-hand penalty is not taken into account for spells).
There are a few topics with build advice for DKS, though not as much all in one place.
Anyone help a newb with Warrior build ... ???class question! (mage advice and links to related topics)
Stat Point Distribution: What's the best way? (for a mage)
Dragon Knight Saga FAQ/Guide