As promised, here is the character list. To the guest who was wondering about the Iron Islands: I'll go ahead and say what happened to them, since it happens between the end of the war and my next chapter. The Stark/Tully forces recapture Winterfell and overrun the Iron Islands. Balon and Theon are executed, and Yara is forced to marry Edmure Tully, with the intention of having the Tullys rule the Iron Islands one day.

The North

House Stark

Robb I Stark, King in the North and of the Riverlands
Catelyn Stark nee Tully, his mother and advisor
Talisa Stark nee Maegyr, Robb's wife and niece of one of the Triarchs of Volantis
Eddard II Stark, infant son and heir of Robb
Sansa Stark, Lady of Flowers, wife of Loras Tyrell
Arya Stark, the younger of Robb's sisters, prone to un-ladylike pursuits
Brandon Stark, Robb's crippled brother, engaged to Shireen Baratheon
Rickon Stark, Robb's youngest brother

Houses of the North sworn to Robb Stark

Roose Bolton, head of House Bolton and Lord of the Dreadfort
Ramsay Bolton, Roose's legitimized bastard son
Rickard Karstark, head of House Karstark, a cadet branch of House Stark
Harold Karstark, Rickard's last surviving son and heir
Greatjon Umber, head of House Umber
Smalljon Umber, his son and heir
Lyanna Mormont, Lady of Bear Island

The Riverlands and Iron Islands

Edmure Tully, Lord Paramount of the Trident, regent of the Iron Islands
Brendyn "Blackfish" Tully, Robb's senior commander of Tully forces
Walder Frey, Lord of the Twins, feels slighted at multiple marriage offers broken
Ryman Frey, senior grandson of Walder, heir to the Twins
Lothar Frey, steward of the Twins
Yara Greyjoy, last surviving child of Balon Greyjoy, married to Edmure Tully

The Wall

Jeor Mormont, Lord Commander of the Night's Watch
Jon Snow, secret son of Prince Rhaegar Targaryen and Lyanna Stark, passed off as Eddard Stark's bastard son
Samwell Tarly, close friend of Jon
Jamie Lannister, the Kingslayer, condemned to live out the rest of his days at the Wall
Ygritte, Jon's lover, a wildling

The South

Stannis I Baratheon, King of the Andals and the First Men
Sleyse Baratheon nee Florent, his wife and queen
Shireen Baratheon, daughter of Stannis, engaged to Brandon Stark
Renly Baratheon, brother of Stannis, Hand of the King, Lord of Storm's End, and heir to the Iron Throne
Margaery Tyrell, wife of Renly
Gordian Baratheon, infant son of Renly and Margaery
Mace Tyrell, Lord of Highgarden
Loras Tyrell, the Knight of Flowers, married to Sansa, lover of Renly
Davos Seaworth, Stannis' most trusted advisor, Master of Ships
Melisandre, the Red Priestess of R'hilor
Tyrion Lannister, Warden of the West and Master of Coin
Varys, a eunuch, Master of Whisperers
Olenna Tyrell née Redwyne, de facto head of House Tyrell
Oberyn Martell, royal ambassador of Dorne
Ser Barristan Selmy, Lord Commander of the Kingsguard
Robin Arryn, Lord of the Vale

Essos

Daenerys Targaryen, Queen of various former Valyrian cities
Jorah Mormont, her trusted advisor
Grey Worm, commander of the Unsullied
Honorius Maeygr, one of the Triarchs of Volantis
Daario Naharis, commander of the Second Sons sellsword company, sworn to Daenerys
Euron Greyjoy, uncle of Yara and pirate of fearsome repute

There's some plot hints I dropped in the list. Eee if you can spot any of them out.