Scarlet Witch is one the most powerful heroes in the Marvel universe, without a doubt. The cinematic universe changes character's powers and abilities to scale well with the movies, making them more interesting. The issue with this is sometimes it becomes unclear what certain characters are truly capable of, and who they can defeat.
A great example of this is Scarlet Witch's showdown with Thanos in Endgame, where she confronts him and almost takes him out all on her own. She's thwarted by the air strike he calls, but she certainly could've disposed of him in multiple ways if she got her way. Captain Rambeau and Darcy Lewis even get into an argument about who would win in a fight, Scarlet Witch or Captain Marvel because it's so unclear.

Amazing Spider-Man Volume 1 #16

This story follows Peter Parker's interactions with Monica Rambeau. To viewers of the show, the name Monica Rambeau will mean something different from it does to Spider-Man fans. In the story, his spidey sense goes off and he thinks there's a threat that needs dealing with. He confronts Monica Rambeau and she blasts him away, revealing a costume underneath before running away.
Essentially, this is Monica's first comic appearance in the Marvel universe and she comes forth as Captain Marvel from this point onward. Unlike in the MCU movie, Captain Marvel is a title in the comics, not the name of a specific person. The powers get passed on from inheritor to inheritor. This might mean Monica will become super powered by the end of
Wandavision.

The Vision

Explaining vision's powers
The Vision is a story that follows Vision's adventure for normalcy after he moves into a suburb in Virginia. He goes so far as to build a home and family with two children all by himself in an attempt to live a quiet life. His desire for a normal human life is reflected in Wandavision.
Whenever Wanda shows off her powers in front of people, he's the first to freak out and say that he wants to go unnoticed as a super powered being. The comic also takes a MUCH darker tone than Wandavision as Vision almost destroys the whole world and a murderer goes on a spree in his new town.

Scarlet Witch (2015)

fighting against an evil off panel
Wanda's backstory, motivations, and powers all come to the light in this modern series. It follows Wanda as she tries to uncover mysteries in the world of magic, and solve disturbances that could wipe out humanity. Scarlet Witch has a different tone than traditional comic book story telling in that it has a sense of horror and mystery that focuses on a single character.
This series is a great place to start for fans wanting to start Wandavision with an understanding of who Wanda is. The Scarlet Witch series tells all about her origins and even the title of Scarlet Witch, which belonged to her mother before her.

House Of M

Cover for House Of M story
In the House Of M, Wanda literally rewrites reality multiple times. This ability is clear in Avengers Age Of Ultron when she sends the heroes to their dream worlds and incapacitates them that way. She does this first in House Of M, sending every member of the X-men and Avengers to their own ideal realities.
When everyone comes to and confronts her, aiming to kill her, she utters the famous phrase "no more mutants" which strips everyone of their powers on Earth. In Wandavision , it's clear she can alter reality in the small town of Westview, but her powers actually can reach across the entire universe.

Vision And Scarlet Witch (1982)

the couple defending their home
Vision and Scarlet Witch seems to be the main basis for the plot of
Wandavision . It follows the events of Wanda and Vision's marriage and them moving to a suburb in New Jersey. They have to deal with trouble and antics in their small town as well, even though they removed themselves from the Avengers.
The show has so much in common with this series that becomes more and more evident with each episode. Halloween is also featured prominently in both, and seems to be the turning point for when Wanda might lose her powers. After episode 5, fans should have a clearer idea of what to look for future episodes.

Avengers Origins: The Scarlet Witch And Quicksilver

The two posing on their origin comic
As of episode 5, Quicksilver has returned to Wandavision and this could change things forever in the MCU. The actor playing Quicksilver changed from the one seen in Age Of Ultron, and became the Quicksilver from the modern X-men movies.
This is huge because it could hint at the X-men making official appearances in MCU movies from here on out. This comic tells the story of the twins, which is much different from
how their origins are explained in the MCU . If Wanda alters reality any more, it could lead to a ton of retroactive changes like the X-men coming into the world of the Avengers.

Vision Quest: Avengers West Coast

cover for vision quest
As Wandavision progresses, it becomes clear that whatever is going on, is starting to fall apart and people are becoming aware of inconsistencies and problems in the reality they live in. In Vision Quest, Vision gets his personality wiped and becomes a husk of the being he was before, losing his marriage to Wanda. The kids between Wanda and Vision are also revealed to be figments of their imaginations sent by Mephisto to send Wanda into a dark mental place. She goes berserk and almost ends the universe but is stopped by losing her memory.

Avengers Disassembled

possessing the avengers
Avengers Disassembled could be a great jumping off point after the events of Wandavision going into the MCU. It's been clear that the TV shows have bearing on the greater MCU and vice versa so when Wandavision ends, it'll likely have huge significance for the greater universe.
In this story, Wanda and Dr. Strange come into conflict. Both heroes have the power to distort reality, and they're drawn together in multiple comics. Here specifically, Strange puts Wanda into a coma after she destroys the Avengers and tries to destroy the world. This could be a great way to transition into the new Dr. Strange movie slated for the next phase of Marvel movies.

Avengers: The Children's Crusade

three different versions of Scarlet Witch
Wanda has been at the center of so many cataclysmic events in her run as an Avenger and X-man, that it becomes clear to many heroes that she's more danger than she's worth. They try to take her out but ultimately fail or can't bring themselves to do it very often. In this story, she finally gets a chance to redeem herself when it turns out Doctor Doom was manipulating her in multiple occasions to become so explosive. This series is captivating to read, and could also become a great transition into introducing Doctor Doom and the Fantastic Four
in future MCU projects.

Avengers #113

The two being lovey dovey
This story is pretty unique in that it deals with themes of bigotry and hatred, extending the metaphors from the page into real life. Wanda and Vision's marriage was seen as taboo in many stories by many characters, and was the cause for a lot of grief in certain situations. In this story, it begins before they marry, and they just act like young kids in love, making out between missions and battles.
Mutants like Wanda were seen as dangerous and less than human by many people at the time, so when people learned she was dating an android, it got even worse. These themes haven't come into play for Wandavision yet, but it could very well be why they two felt they needed to hide so much during Avengers: Infinity War.