Pick up the Felsteel set for your Legs (until you get Timewardens) and gloves as they are easy and they provide alot more gem slots. If you plan on tanking 10mans you should be gemming +def until you get to 490 and then switch to Stam. Do a Bot and Mech to get the belt from the the key quest. There is also a good Green belt from a quest in Netherstorm with some +def on it until you can get that.  I think the shoulders from the Durnholde quest may be better as you get 2 gem slots and a little parry rating.

Enchant for stam, not strength (Armor kits are great until you can get the chants.) There is also a craftable blue quality +def cloak. The mats are pretty cheap if I remember right.  

The Path of Conquest chain in SMV will get you another tanking ring. Or you can try to get in on a Kara run and get yourself friendly with the Violet Eye. 

Also, on your spec. Cruelty > Booming voice for threat generation and you definitely want Focused Rage (I'd take the points out of Imp Shield Bash and Imp Shield Wall or Imp Taunt (though Imp Taunt is nice to have in 5 mans). 

Ging,

You might also hitup http://www.tankspot.com/forums/   

They have alot more information that is warrior specific.  Most of my data comes from Tankadins, but pre-raid the gear is mostly the same because they didn't work very hard to make sure us tankadins were taken care of before Kara.  (Which means we used your gear.  :D)

The quest-chain for the Enigma starts here:

http://thottbot.com/q10437

It is out in Netherstorm.  As a tank, your going to need a full group, or some REALLY fast-running friends to do the last step of this quest.  When I did it, I had a Kara-Geared prot warrior, a retadin, and myself healing as a protadin (boy that was a joke).  I ended up proving you CAN be bandage-specc'd for a boss fight.  :D   My recommendation, run Bots/Mech and bribe your group once you finish an instance-run because the fight isn't as hard as Freya as long as you don't have to may melee'rs.

 You might also eyeball my blog "Keeping with the Tankadin" for some of the gear that doesn't have +Spellpower or +Int.  If neither of those two is present in the gear, it is just as viable for you as a beginning Prot-warrior as it is for me as a Tankadin.

Ginger,

First let me say that as vague as it was, the previous poster was correct to a point.  You'll be needing to run Heroics to really get your tanking down, but you'll want to start with 5mans first until you can get your  defense much closer to 490.  There have been phenomenal tanks not even close to 490 on Heroics, but in your own words your not the best tank.  Let's get your gear there while getting you used to the idea of tanking ( Regular 5mans ) and we'll worry about the little details later.  :D

I would start some Steamvault runs to get yourself the [Strength of the Untamed] from the Reputation reward, and pickup the [Devilshark Cape] from SV's boss along the way.

Go ahead and spend the $$ to pick yourself up a pair of [Bracers of the Green Fortress] and if you haven't done your Dimensius the All-Devouring quest, pickup your [Dabiri's Enigma], which will be a fantastic step-up.  If you have done the quest and didn't get it, the second boss in Slabs drops a comprable piece.  Not very often though. [Adamantine Figurine]

Keep the [Legplates of the Bold] as you will use them later, but the [Timewarden's Leggings] has more slots to drop some +12 Sta gems in.

I would look into an upgrade for your shield.  Either the Netherwing Protector (from the Netherwing rep quest-chain) or the [Crest of the Sha'tar] for a quick-and-easy should you have the rep.  If you've been keeping up for dailies, the [Dawnforged Defender] is a very nice piece as well.  I would rate the shield last under "needed" upgrades because your's is fairly decent.  I would replace that +sta buff with a +def or +block instead and let your +12 gems take care of the sta.

From there, upgrade those +9 sta's to +12's and see your local enchanter about some +Dodge, +Agi, and +Def enchants.

Finally, start bouncing around the AH looking for random Armor kits.  They are generally cheap, but can be used to balance a little from the lack of gear.

Hope that helps!

WTB some help/advice

BUMP