Stat points
Strength: enough to wear your equipment, 50 or 156 is up to you since you will have an excess of stat points. When I played my Ladder Meterorb sorc, she had over 100 stat points left at lvl 92 because I was too lazy to allocate them.
Dex: Enough to gain full block with your shield (see Dottie's comments on blocking in the Blizzard sorc guide). If you use an upgraded Viscerataunt as I would suggest, you need about 200 dex at lvl 90.
Energy: Base to 75.
Vita: Everything else you can spare. Do not enter Hell difficulty with less than 300 in life. A sorc gets 2 life for 1 point in vita, so it's not a very good payoff though. Using items with life on can often be more efficient.
Skill points
1 in Warmth
1 in Teleport
1 in Static Field (optional, it's convenient in Normal and Nightmare but not necessary)
20 in Frozen Orb
8 in Cold mastery including the bonuses from your equipment
Then start developing the fire tree:
20 in Meteor
20 in Fire Mastery
The rest in Fire ball
Put your first skill point in Warmth, mana is every new sorcs worst headache. You can use one Ice Bolt to freeze the monster, and then hack it down with melee. At lvl 6 you get Frost Nova, use it to chill monsters and melee them down while they are frozen. If you have mana enough, you can also use Glacial Spike when you become lvl 12.
At lvl 24 you get Blizzard. Use it is the same way as Frost Nova. At lvl 30, you finally get your main skill, and life will become bright and easy
Equipment
Early in the game you need mana, so socketed items with sapphires to increase your mana pool, and skulls to increase your mana regeneration, are very useful. Don't be afraid to use up your gems, gems are very common in D2. You also need a 3-socket shield with diamonds (a 3D shield) in order to get resists. By the end of Normal, you should start looking for items that give you +skills, MF and resists.
Suggestions for the average player:
Weapon: Rare sorc Orb with +skills and resists.
Shield: Viscerataunt sck with perfect diamond and Moser's Blessed Circle socketed with 2 perfect diamonds are very good. Otherwise a 3D shield with high block, Sigon's with perfect diamond.
Armour: Skin of the Vipermagi is the best armour at this stage. Smoke,
Helm: Tarnhelm is very good with both +skills and MF. Runeword Lore, Peasant's crown or a rare circlet with +skills and resists.
Belt: Nightsmoke, Look for resists and mana.
Boots: Look for MF, faster run/walk and resists.
Gloves: Frostburn or rare gloves with MF and resists. Look for Chance Guards.
Amulet: Rare or magical amulet with + cold skills.
Rings: Look for +mana and resist.
"Godly", best possible equipment
Weapon: Oculus sck with Ist.
Shield: Upgraded Viscerataunt sck with perfect diamond or Um. Some people use Stormshield for high block and damage reduction, but I prefer the +1 to skills you get with Viscerataunt, the4 Meterorb sorc is such a strong build so she survives perfectly fine without a Stormshield.
Armour: Tal Rasha's Guardianship sck with perfect topaz
Helm: Harequin Crest (usually called just "Shako" for short) sck with perfect topaz.
Belt: Tal Rasha's Finespun cloth
Boots: War Traveller or rare boots with MF, faster run/walk and resists.
Gloves: Perfect Chance Guards.
Amulet: Tal Rasha's Adjudication
Ring 1: Stone of Jordan
Ring 2: Wisp projector with high absorbtion
With this equipment, you have an optimal balance between MF and killling speed
Mercenary
The best merc for a Meteorb is the Holy Freeze (defensive) merc you can rent in Act II, Nightmare. He will kill the few bossmonsters you will meet that are both fire and cold immune. Your merc needs good equipment to survive, so look for armour and helmet with high defense, damage reduction (DR), and resists. Rockstopper and Shaftstop are excellent. He also needs a good weapon, so look for etheral rares or uniques with high damage (merc's can use ethereal items forever, and etheral weapons have a damage bonus whereas ethereal armour has a defense bonus). He must also have life leach, so either socket your weapon and put an Amn rune in, or use items with life leach. My merc Azrael uses Tal Rasha's helm, Levithan and eth Reaper's Toll sck with Shael for IAS.
Gameplay
Since both Frozen Orb and Meteor are timed spells, you use Fireball in between. Frozen Orb does not make so much damage in Hell, so I usually start with an Orb to freeze the monsters, then I go Fireball-Fireball-Meteor-Fireball-Fireball-Meteor, with an Orb thrown in if the monsters recover from the first one before they are gone.
The most difficult monster in the game you will encounter, is probably Duriel at Normal. You are weak and have no powerful skills, and he will kill you in one hit. I usually but a staff with Blaze, and then walk around in the crypt until Duriel is gone. I use static also, but it still takes some time. Don't forget to feed your merc with healing potions constantly.
When you reach Mephisto at Nightmare, you can start doing MF runs. Start a game, go to the Durance of Hate lvl 2 Waypoint, teleport around the wall until you find the staircase to lvl 3. If you dare, teleport through the wall to your characters right and then over the moat to kill Meph swiftly. However, this is risky if you char is not so strong yet. Killing Bremm and his mates may be a good idea, you get decent items and XP for them anyway. When Meph is gone, exit and repeat.
Many players on Bnet do endless MF runs in order to get the perfect items. I don't think it's very funny to do 6000 Pindle or Baalruns, so I MF by playing areas instead. The best items are mostly dropped at Hell difficulty. I like to play Act IV for instance, River of Flame is an excellent MF area, as is Chaos Sanctuary. I've got many of my absolute top items such as a Ber rune, Windforce and Arachnid Mesh from monsters in these two areas. Another good area for MF:ing is Worldstone Keep. There I found my first Tal Rasha's armous, IK armour and other nice items. Other monsters that can drop good items include Mephisto and Pindleskin at Hell difficulty. Many people who do many Mephruns (a "Mephrun" is when you start the game, go directly to Meph, kill him, take the drop and exit the game) use the Moat trick. The Moat trick means you attack Meph from a safe distance at the other side of the Moat.
1. Teleport to Durance of Hate lvl 3 as I described above.
2. Teleport in a straight line towards Meph, carefully avoiding the High Council and other monsters.
3. As Meph move towards you, you can start reducing his hitpoints with Static field if you have it.
4. Make Meph follow you closely, then teleport over to the other side of the moat again.
5. Position yourself so Meph stops attacking you because of the distance. Back towards the entrance, again avoiding the Council. Meph usually stops attacking when you are about half a screen away. Now, you can spam your Meteors on him safely. (This works fine for most ranged attacks such as Blizzard, Firewall, Bone Spirit or Lightning Sentry.)
A high level Meteorb Sorc with max block takes out Meph faster without using the Moat Trick, but when your char is still young and has no really good equipment, the Moat trick is a safer way.