First, are you leveling a weapon, to keep it as a weapon, or, are you going to relayer it? If you are going to keep it as a weapon, then below is a general guideline
This is a subject upon which many debates have occurred
What it all comes down too, is your play style. Or, at least the style of playing you want to get too.
This might help you choose your style a bit (posted by Heyyo):
The main point of a weapon is to deal damage. All the other stats can be placed on relayers or be obtained from other gear. So, the object is to maximize the damage you can deal with your weapon. To do this you need:
-strength (adds base damage regardless of weapon)
-weapon hits (lightning, fireball, and harm/magic arrow if you have the points)
-spell damage increase (this will increase the damage of the magic hits, but is also something you can place on relayers) - you don't need this, but if you have the extra points it doesn't hurt
-the leeches (mana/life/stamina) mana leech is necessary to let you spam your weapon specials (for a bow I have 45% and almost never run out, a whirlwind weapon you would only need 25-30% as you hit so many mobs on a whirlwind). Life leech is like a magic hit spell, but it gives you hp, which is a huge bonus if your poisoned or have mortal strike on you. Stamina leech is ok, but not necessary. If you don't play the chivalry route then it's an absolute must to restore your stamina, but with the divine fury spell you can just regain stamina that way.
-hit lower defense is a must for single targets with high hp. It lowers their defense, and thus increases your offensive hit chance and total damage (I think total damage, but not 100%). On a whirlwind weapon it's not bad, but usually you use whirlwind for a bunch of low hp creatures. On the other hand with a double axe or war hammer you can both do whirlwind and do massive damage to single targets, so lower defense is recommended on those as well.
-hit lower attack - Not a fan, once you get insta heal and high enough hp with several relayers with the reflect physical damage stat when mobs hit you, you can deal several times that damage back. If you have lower attack the mobs won't hit as hard or often, and lower your dps
The only non damage stat many use is adding 8 to hit points because once you get insta heal and all your other stats maxed that's the only thing you cannot max out. The % magic hits refer to the likelihood that that magic spell will hit on a successful strike with your weapon. So if you have 60% lightning you have a 6/10 chance on a successful weapon strike, 40% fireball would give you a 4/10 chance. The higher the percent is the higher your average damage will be.
