She is located at 40,88 in Razorfen Kraul in barrens, when u enter the instance go to the right side, its a long way,I spend like an hour to find her, but u can get there, I do it with my lv44 hunter, piece of cake...lol yeah she talks too much... I hope it helps

The quest give is in Thalanaar - which is on the edge of 1k needles and Feralas (near the Flight Path)

You must get the journal from the corpse at the bottom of the great lift in 1k needles before you can get this quest.

to aquire the medallion you'll need to kill razerflank, she is the last boss in RFK - and yes she does talk alot :p

The shield you get from the quest has an iLvL of 35+, as such you can get +18 Stamina on it, making it the best Twink shield to date.

This starts off from Lonebrow's Journal.
Note that this quest does not appear ! on the minimap, so you must find the dwarf body yourself. but it's simple. Go down the Great lift, take your right and go to the dead dwarf. Click the journal.
After you turned the quest in Thalnar(Feralas or w/e it's called), go back up the great lift. and RFK is very close to it.
Just stay to your right. There are boars below you at a certain point. Ignore these. Even if you/your group are planning to do the escort quest, it's much quicker to jump down after Charlga.
You'll soon come across an intersection with 3 other paths. The ones to your right/left lead to optional bosses. For the Medallion, keep going straight.
Once you reach the bat cave, killing the guards of the force field is just another optional boss. You might also come across a rare bat. Once you see more razorfen, keep going, Charlga Razorflank is hiding in a hut, so make sure you don't just charge up there unless you're a high lv.
She mainly casts Chain Bolts, so casters will want to stay back. When around 30% health, she will cast a shield, wiping all debuffs, and becoming immune. Once it's gone, continue and she'll be dead

Ignore the previous comments, the quest counts for Loremaster of Kalimdor as of Patch 3.0.8.