Dual wielding is the most effective melee technique, and mages should dual wield weapons with the largest magic damage bonuses / enchantments available.
Archery is quite effective, and playing a ranger in DKS (since I did D2:ED as a warrior), I stopped distributing stat points after level 15 (on nightmare difficulty). Early levels as a mage or ranger you may need to fall back on some melee combat (or run away), but most of the opponents early in the game don't have ranged attacks, so you can take most out from a distance, or at least do damage before they can get to you. A bow for a warrior is very useful early to mid game to draw opponents to you, rather than rush into what may be a larger group than you can see, and get a little damage in (no need to invest in any bow skills); mid to late game bows are still handy to break crates and vases, etc, and take out weaker opponents that try to run away.
For the creature (available about level 10, if you are careful and know where to go; normally level 12/13ish), in the D2:ED playing a warrior, and DKS with a ranger, I much prefer using a mage head. Some people like a warrior creature when using a ranger/mage build, but I found it to be much more helpful, more aggressive and get in the way much less as a mage; as a warrior, in large spaces (like the flying fortresses), it could run off to attack a distant opponent, and draw attention from other opponents that were not otherwise aware of the fight yet. It is still helpful even before you get any replacement heads to add skills.
Anyone help a newb with Warrior build ... ???Just started this game ranger advice / link
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 - contains a list of quests, enchantment and potion formula, equipment lists, etc