Poison+Summon necr

1 Amp Damage
1 Bone Armor
1 Lower Resistance
1 Corpse explosion
1 Summon Resists
20 Skeleton
20 Poison Bolt
20 Poison Explosion
20 Poison Nova
20 Skeleton Mastery (Max this one last)
With these skills you should be done at level 94 with the skill quests.

Stats:
(this section is in my opinion always more of a personal preference.)
Strength: Enough for gear
Dexterity: None/Enough for max block if thats what you like.
Vitalty: All remaining points
Energy: None

Gear:

Helm - Necro Spired Helm(cant remember name) or 08 Shako

Jewelery - Anything with most + skills or Undead rings for more poison damage

Armor - Bramble, The thorns will help skeletons and the + poison damage will help you.

Boots - Blade boots (tal ist pul ko) +2 all skills and the main source of magic find

Gloves - Trangs set gloves

Shield - this is another one of those things I think is a personal preference. I use boneflame for +3 skills

Weapon - Death's Web

Belt - Arachnid mesh or Monty Python's if you can find it.

Sockets - Again.. personal preference. I use Divine Diamonds for resistance in shield and after max res I use ALL poison facets. Remember FCR is not important for this build.. You can not stack the poison damage so once a nova or bolt hits you have 2/4 seconds before you need to cast it again.

Strategy:
You basically need to determine weather your damage will kill the monster/s faster or you skeletons' damage. It is usually the skeletons but some Physical immunes can be slow. Once you determine what is faster you need to use the appropriate curse.
Also remember that corpse explode is 50% physical damage and 50% fire damage so both curses will help, amp just helps a little more. Unless of course they are physical immune.

Mercenary:
Another topic of personal preference, I use act 5 merc for Battle Orders and Shout.
The gear however is not so much personal preference.

Helm - Caster crafted helm with meditation aura.

Armor - Blood crafted armor with Concentration aura.

Weapon - Beast/Faith with Fanaticism aura

Gloves - Elements enraged with Conviction aura (Conv does not lower poison res but it does lower their defense so your skeletons can hit easier, also lowers fire res for corpse explode.)

Boots - Hover Boots with vigor aura. Skeletons are slow..

Amulet - up to you.

Rings - I use the set ring with holy freeze but its up to you.