IIRC in the book Danny actually can understand Astapori, but just choose play dumb, it wasn't mentioned in the TV episode )

- Jon & Ygriette send over the wall
- Rebellion/Massacre at Craster's Keep
- Selling of dragons, betrayal at Astapor for the Unsullied
- Bran & Jon cross path at the abandon keep during Jon's escape
- Trial of Hound, Duel of Berric & Hound, Arya & Hound traveling together, showdown at crossroad inn.
- Jamie loosing his hand
- The 3 weddings, Tyrion & Sansa, Tully & Frey, and Jeoffrey's wedding
- The red wedding, massacre at Twin
- King's wedding, poising
- Escape of Sansa & little finger
- Trial of Tyrion, dueling between Mountain & the Viper
- Escape of Tyrion, death of Shae & Tywin

Trial & duel of the Hound
Jamie loosing his hand

in the book, Melisandre never left Stannis and met up with the brotherhood
and never had Gendry with her
So far in the book, Gendry's fate are still unknown, as he's still hanging out with the brotherhood.

RIP Ros, your titties will be sorely missed

Littlefinger
He poisoned Jeofrrey at his wedding, and blamed it on Tyrion
also he's the mastermind behind the poisoning of Jon Arryn thru the hand of Lysa, and put the blame on the Lannister
He then killed Lysa at the Vale and put the blame on a singer
Although it's not mentioned in the book, most likely he's the one behind the attempted assassination of Brandon, then put the blame on the Lannister

Spider
In secret, he's still loyal to the house Targaryen
He switch Aegon Targaryen with another baby during Robert's rebellion, and smuggled him out across the sea to be raised as a leader
He's plotting to bring down the house Lannister by sabotaging their alliance with the Tyrells
He will kill Grand Maester Pycelle, and Kevan Lannister as well to achieve that goal.

Ygritte got killed.

Bran - went down the well, met white walkers, rescued by coldhand, end with meeting with children of the forest.
Jon - Defended Castle Black from wildling invasion from other side of the wall, deadth of Ygritte, another battle at other side of the wall with Mance Ryder, Stannis came to rescue, end with Mance defeated & captured.
Arya - Crossroad Inn incident with the Brave companion, leave Hound to die, reach port, traveled to Bravosi, end with admittance to the temple
Sansa - Approached by Ser Dontos, escaped during King's wedding, went to Vale, end with death of Lysa thru the moongate.
Tyrion - Attended another wedding, insulted King again, King died, suspected of murder, wife missing, end up in dungeon, trial by combat again but lost this time, escape from dungeon with spider's help, end with killing father & lover.
Jamie - going back to his King's guard duty, promoted to commander post, conflicts with the kettleblack brothers & Cersei, angry with Cersei, end with sending Brienne to look for Arya
Daenery - attracted to Daario, probably will share bed with him, Jorah went into jealous rage, end with conquering of Meereen

They planned to seek refuge in Castle Black initially after escaping from Winterfell, but after their encounter with the Reed sibling, Jojen had convince Bran that his dream about 3 eye crow aren't just simply a dream, so they went to seek for the 3 eye crow instead of joining Jon
Bran was convince that the 3 eye crow will be able to make him walk again
Also they prefer to keep their secret of being still alive, including from Jon, cause if the kingdom knew that the heir of Winterfell is still alive then they'll be in danger as well.

Ghost was left at the wall before the climb, they can't climb with the direwolf
Ghost will eventually find its way back to castle black

Letter? got such letter meh?I don't recall reading it in the book

Anyway...
Jon is a *******, and he has taken the Black, so it makes him as heir to the Stark as double null & void
Also the rest of the confirmed living children (Sansa) should take precedence over a ******* as heir

Only the King or the existing Lord of the House can re-instate a ******* as a heir to the house, but no one can retired from the Night Watch, not yet in history of Westeros anyway...

In the next seasons we will see Stannis pressuring Jon to claim back Winterfell, and want to instate him as the Lord of Winterfell