It's interesting for a number of reasons: it tells the Biblical story of the Moabite revolt from the other side; it contains the earliest extra-biblical mention of YHWH, and it may (depending on how you read it) mention the House of King David. It's also a look at what a king deemed worthy to record: battles, building projects, and his devotion to his god, Kemosh.
Wikipedia has a rather good literal translation as well as the story of the stele's discovery. The Israelite side of the story is in 2 Kings 3. The biblical version describes, "King Mesha of Moab ... used to deliver to the king of Israel one hundred thousand lambs, and the wool of one hundred thousand rams" and also mentions that Mesha sacrificed the eldest son of the Edomite king to his god Chemosh.
For your pleasure, I present my translation in verse, a la Thomas Macauley. The spelling of the proper names is subjective since the Hebrew/Moabite language does not record vowels. The last lines of the stele are quite damaged.
I am King Mesha, Kemosh-yatti’s son
He ruled 30 years, and then my day begun.
After my father, the Dibonite lord,
I ruled over Moab and saw my reward.
I built this high place for Kemosh in Qarcho
By his stern grace I had quashed all of our foes.
Omri was then-king of Israel’s land
He swore he would show me the might of his hand.
His son also ruled and he swore to oppress
And while Kemosh was angry, he found brief success,
But city by city, I did repossess.
Forever I conquered his house and his nation
Devastation I wreaked for all generations.
Omri had ruled in the land of Medaba
For 40 years clutching his desert-derata.
But Kemosh returned it to Moab and Mesha
And I, King of Moab, restored its foundation.
Baalmeon I built and I stockpiled its waters
Qiryaten I built; Ataroth I slaughtered.
The once-king of Israel had built it for Gad
But I gave it to Kemosh, and all that they had,
The hearth-altar of David I dragged to Qiryot
I settled there men of Sharon and Machrot.
Now Kemosh said, “Go, from the Ivri take Nebo!”
I travelled by night--“cherem” was my credo.
I fought through the dawn to the heat of the day
Men, women and children, all were my prey,
Seven thousand I killed, nor once did I falter.
And the vessels of YHWH? Ashtar-Kemosh’s altar.
Yahaz was once built by Israel’s king
But he ran from his city when he felt the sting
And the lash of Kemosh who drove him out
So I seized all his captains and finished the rout.
I annexed it to Dibon, by his own chosen men,
I made Qarcho better than once it had been:
The acropolis, gates, its towers and waters
A fine royal palace, all built by my orders.
In the midst of the city, no cistern was there,
So I built water channels and made it my care
Each man for his home would have its own well
All built by my prisoners from Eretz Israel.
Aroer I built, and the roadway of Arnon
The ruins of Bet-bamot, I next turned my eyes on;
Bezer lay in ruins before Mesha of Dibon,
Bet-Medaba, Diblaten and Bet-Baalmeon,
All these I rebuilt, and for many were rubble
The heaps became towers and Moab redoubled.
The men of all Dibon stood in formation
For I held all of Dibon in my subjugation.
I ruled over hundreds in my annexed towns
I grazed my fine flocks in lands all around.
The house of old David had dwelt in Hauranen,
But Kemosh said, Mesha, go down, put your hand in
He delivered Hauranen, just as he swore it,
In my days, the great days, Lord Kemosh restored it.
[Reconstructed final lines]
From the high place of justice, I rule Moab’s land
By Kemosh’s will and the power of my hand.
Secure in my kingship, I say from my throne:
Woe to the one who smashes this stone
Woe to the king who erases my name
May he go down to death with no son, with no fame
The throne of my kingship will overturn—never.
Mesha rules Moab from now till for ever.
Epilogue
They say I gave innumerable flocks
“Paid tribute” is their taunt.
They say I sacrificed a prince
Believe it if you want.
My stele is as black as night
Endless is my fame
Son of Kemosh, Moabite,
Mesha is my name.