This is a rather unusual question and, surprisingly, books that feature spiders are not as niche as people might think. I've actually read quite a few of them, so here is what I can suggest:

1 American Gods by Neil Gaiman

Yes, I know that technically Mr. Nancy is not an actual spider, but he is the Trickster God Anansi who has the ability to turn into a spider and command other spiders, so I still think this counts.

2 It by Stephen King

Once again, I know that everyone remembers Pennywise as a scary clown, but in his real form he is actually a giant spider, which is even more terrifying.

3 The Lord of the Rings by J. R. R. Tolkien

I would say that Shelob featured prominently enough in the book to be included in this list. I actually remember having nightmares about her after reading The Lord of the Rings as a youngster, and I think a lot of authors who included giant spiders in their books got the idea from Tolkien.

4 Spiderlight by Adrian Tchaikovsky

Just the cover art of this novel is already enough to send any arachnophobes screaming, so I would recommend this book if you are into giant spiders. The Great Mother is the most terrifying spider in the story, but when one of her spawns takes on a human like form, things get even more disturbing. At least it doesn't wear a clown costume like IT.

5. Perdido Street Station by China Mieville

This book features a character called "The Weaver"and it wins my vote as the most disturbing spider in literature. It's not an actual spider and more of a multi-dimensional being who just happens to look like an enormous spider, but still. Oh and another thing, it constantly babbles out free-verse poetry, which is about the last thing that I would want to hear coming from a giant spider, especially one that can move through dimensions.

As far as I can see spiders only tend to feature prominently in either horror books or children's books. Since there is already an abundance of horror recommendations, I'm going to recommend a couple of very nice children's books.

1. Charlotte's Web by E.B. White

Charlotte is a friendly barn spider who lives on a farm. She befriends one of the protagonists of the story, a pig named Wilbur, and comes up with an ingenious plan to save him when he is marked for slaughter. *Spoiler alert* she manages to save Wilbur, but doesn't live much longer herself, so it is a bit of a sad tale. It does have a happy ending as her children take up residence in her old home and become friends with Wilbur too.

2. Miss Spider's Tea Party by David Kirk

This rhyming story with its colorful illustrations is great for the young ones. The star of the story is Miss Spider, who can't understand why people don't want to accept her invitation for tea. She is determined to host a tea party, though, and in the end her efforts pay off.

3. Walter's Wonderful Web by Tim Hopgood

If you want to introduce your kids to shapes in an engaging manner, then show them Walter's Wonderful Web by Tim Hopgood. It's the story of a spider that wants to build the perfect web and tries out all kinds of different shapes. The art for this book is really charming and the story is educational, but still fun.

4. Be Nice to Spiders by Margaret Bloy Graham

This is a cute book about a spider who ends up living at the zoo and improving the lives of all the animals there by spinning webs to catch the flies that are buzzing around. Things almost go badly wrong when the zoo has a large scale clean-up operation, but in the end everyone recognizes the valuable contributions from the spider.

5. Frank the Seven-Legged Spider by Michaele Razi

Frank the Seven-Legged Spider is all about a spider named Frank who wakes up one day missing a leg. Frank is obviously very upset about this turn of events, but soon learns that even with seven legs, he is still a spider and can live his life to the fullest. If you want to teach your child about coping with a disability, then you should enlist the aid of Frank.

6. The Hugely-Wugely Spider by Ethan T. Berlin

Everyone knows Itsy-Bitsy spider, but it’s about time the world learns about the slightly larger, Hugely-Wugely spider. Hugely is a little large for downspouts, but his size still ends up saving the day and making him a hero.

7. I'm Trying to Love Spiders by Bethany Barton

This one is for very, very young readers as it is mostly pictures and not words, but it still tells an enjoyable story that the young ones who hate spiders can really relate to.

All of these have been deemed as certified "awesome" by my kids, so if you have young kids who have a fascination with spiders, then any of these books should delight them.

Ironically enough, the most disturbing book that I have ever read where spiders feature very prominently was a non-fiction book by Gordon Grice. The book came out quite a few years ago and contain the kind of stuff that would probably cause it to get blacklisted by PETA if it was released in this day and age. The title of the book is The Red Hourglass: Lives of the Predators and while it does include chapters on rattlesnakes and mantids, but the scariest ones are about black widows, brown recluses and tarantulas. If you ever doubted that a nature book could give you nightmares, then read The Red Hourglass. A lot of the stuff in this book is very disturbing as the author had no qualms pitting spiders against each other and writing in great detail about the ensuing carnage. Before I read this book I was cautious of spiders, but not exactly terrified. After reading it I shivered whenever I saw anything with eight legs, so be warned.

I have never really been afraid of spiders as they are everywhere where I grew up, so you could say that I am used to them. I say this because I can recommend a couple of novels that feature spiders, but I can't really call any of them scary. I would say that for somebody who is afraid of spiders or have a phobia about them, these books could potentially be scary to read, but use your own judgment.

The first one is Salticidae by Ryan C. Thomas, who is the same author that wrote The Summer I Died. It is basically about a mining company that unleashes all hell in the Congo when they try to mine a mountain where giant jumping spiders reside. These things can jump thousands of feet far and they quickly develop a taste for the humans that foolishly set them free. It's not just the people from the mining company that have to scramble for their lives either as there are a bunch of other characters in the Congo for various other reasons too. This gives the spiders plenty of targets to brutally feast on.

The other book is Spiderstalk by D. Nathan Hilliard, which looks like it is going to be some type of b-movie horror fest if you judge it by the cover. It is not, though, and while it does indeed feature giant spiders, the story is also quite intricate and well thought out. It is about a down on his luck man who ends up unconscious in hospital after a car wreck. When he wakes up, he discovers that his brother is missing along with his whole family and the only clue he has to finding them is a weird photo of a spider that they sent to his phone.

Lastly, there is a science fiction novel by Adrian Tchaikovsky that has an entire planet full of evolved spiders as part of its story. These spiders became uplifted after some meddling by human scientists, but now inhabit a planet that was initially terraformed for human life. When humans flee Earth to find a new home, they rediscover the planet that their ancestors prepared for them, but also find that the spiders are not going to be keen to give up their home. I liked this book as it is usually aliens invading Earth and not the other way round.