Since this is pretty much a Stark book – so much of it is told from the POV of the Starks – we get introduced to a lot of their servants. In fact, if you check out the Appendix, most of the Stark servants listed actually show up, which is not true of the other major houses. There are more and less important servants; but hopefully this guide will help you keep them straight.
An older man, Luwin is the wise man and advisor for the Starks at Winterfell. Like all maesters, he wears a chain that symbolizes both (a) his service to the family and (b) all that he knows. So, part of his chain is iron, which means warcraft, and part is silver, which means healing (42 Jon 5).
Luwin is a nice contrast to the other important maester in this book, Pycelle. Luwin is wise and helpful, and he seems dedicated to the Starks. Pycelle, not so much: he should be dedicated to the royal family, but he seems more dedicated to the Lannisters.
One cool thing about the maesters is that their robes have lots of pockets: "Luwin was always tucking things into those sleeves and producing other things from them: books, messages, strange artifacts, toys for the children" (7 Catelyn 2.28). That's not just a funny image, but also a reminder of how wide the maester's role is. (He has toys for the children? Awesome.) Still, we should note that, though the maester knows a lot about history, he doesn't much believe in all the old stories. And since dragons are coming back to the world and the Others seems to be rising, he might not be the best advisor for the future.
Syrio Forel is the only reason that Arya is still alive. Arya is a wild child (her father says she has "the wolf blood" [23 Arya 2.55]), but Syrio teaches her some discipline while he's teaching her how to fence with a sword. Syrio is from Braavos, so he doesn't fight like a knight (standing there and hacking until the other guy drops); he fights by being more dexterous and flexible than his opponent. And this is just what Arya needs to learn since she's off on an adventure (yuck, we hate adventures) where she won't be able to take anything for granted: she'll need to see what's in front of her and be flexible when the situation changes.
Captain of the Stark guard, Jory Cassel is also something of a Stark friend, which we can see by the fact that he eats with the family (23 Arya 2.18) and jokes with Eddard. Arya especially is friends with Jory; but Sansa is a little ashamed that he's not more fabulously dressed when he competes in the Hand's Tourney (30 Sansa 2.6). So Jory helps us see the difference between tomboy Arya and status-conscious Sansa. He's a nice guy, and like a lot of nice guys in this book, he doesn't survive. He's killed by Jaime Lannister's men when they attack Eddard in the street (36 Eddard 9).
Ser Rodrik Cassel
The reason Jon Snow is such a good fighter and such a bully is that he was trained by a knight. Ser Rodrik Cassel starts off the book as Master-at-Arms at Winterfell (with white whiskers of which he's very proud), so he trains all the Stark boys in combat. (And maybe in shaving?)
This guy is also just generally brave and loyal. He takes Catelyn Stark to King's Landing (even shaving off his whiskers, which shows how dedicated he is to the Starks); then he helps her to capture Tyrion; and at the end of the book, he returns to Winterfell to train more soldiers for the Starks. (And he does all this even though he's a little on the old side. Although, given life expectancy in this world, what's old: forty?) He has a daughter, Beth Cassel, and amazingly, she's also alive at the end of this book. It's pretty much the only example of a family not losing any members.
The Steward of Winterfell (and father of Jeyne), Vayon Poole comes south with Eddard to take care of his household. This proves to be a poor career choice since he ends up dead after Cersei takes over. But still, before he dies, Vayon Poole teaches us something about how this world works: House Stark is a very powerful house and House Poole is a minor house. This means that some of the Stark servants are themselves from noble houses.
Mordane is Sansa and Arya's teacher and, like most teachers, she's here to make the independent child's life difficult. "Septa" is a title, meaning that she's a minister in the Faith (like a nun); but it also indicates that she's kind of traditional: she likes girls to be girly, which means that she constantly tries to get Arya to fall in line.
Through most of the book, we don't love Mordane; but when Cersei takes over and captures the Starks, Septa Mordane dies like many of the Stark servants, so maybe we underestimate her loyalty to her house. We might want to reconsider Mordane since we tend to only see her through children's eyes and these children don't always know the whole story. So: Mordane is a tough cookie, but her heart seems to be in the right place.
(Also, Castle Winterfell has a librarian, Septon Chayle, who doesn't have any real part in this story. But it is neat to see how septas (nuns) and septons (monks) serve a social function in this story. It's also interesting that they're there because septons and septas follow the Faith, but the Stark family worships the Old Gods.)
A List of Guardsmen (and How They Die)
Hallis Mollen: named Captain of the Guard at Winterfell after Jory Cassel goes to King's Landing; Hal Mollen often states the obvious (64 Catelyn 10.26). Status: Alive (because he stayed in Winterfell, where it's safe).
Alyn: a guardsman who becomes captain after Jory's death, and who later gets sent out to capture or kill Gregor Clegane with Beric Dondarrion's group. Alyn also took part in the tournament, but didn't do so great. Status: unknown.
Tomard a.k.a. Fat Tom: a friendly guard, Tomard becomes captain of Eddard's guard for a while (from chapters 46 to 50). Status: killed during Cersei's takeover.
Desmond: a guard. Status: killed during Cersei's takeover.
Harwin: a guard, son of Hullen. Harwin takes part in the tournament for the Hand of the King and later gets sent out with Beric Dondarrion's group. Status: unknown.
Jacks: a guard. Status: killed during Cersei's takeover (probably).
Porther: a guard. Status: killed during Cersei's takeover (probably).
Varly: a guard. Status: killed during Cersei's takeover.
Cayn: a guard. Status: killed during Cersei's takeover.
Heward: a guard. Status: killed in the street fight with Jaime's men.
Wyl: a guard. Status: killed in the street fight with Jaime's men.
Quent: a guard at Winterfell. Status: Alive! He's alive!
Wayn: a guard at Winterfell. Status: Also alive. Wow.
Hullen: master of the stables who goes to King's Landing, and, of course, dies when Cersei takes over.
Joseth: master of the stables at Winterfell (after Hullen left).
Donnis and Lew: servants. Just a reminder that there are a lot of servants in this book that we barely (or never) see. Who serves all that food that Robert Baratheon eats, for example?
Mikken: the blacksmith, maker of Needle.