My youngest went through a phase where every single book she wanted had to be about school. The first day, making friends, the teacher, recess, homework, you name it. I completely understand why. Starting school is such a huge deal in a kid's life, and books give them a way to practice those feelings before they happen or make sense of them afterward. But finding books that actually felt real and not totally babyish was harder than I expected. The easy reader section at our library was full of stuff that felt too young, and the chapter books seemed to jump straight to kids dealing with stuff my kindergartner hadn't even encountered yet. So when we finally found books that hit that sweet spot, I took notes.
One that we read over and over was "Dear Diary" by Judi Press. It's written as diary entries from a girl named Erin who grows a prize pumpkin with her dad, and my daughter loved feeling like she was getting a peek into someone else's real life. Tony Dungy's "You Can Do It!" was a surprise hit because it tackles that question every kid gets asked about what they want to be when they grow up, and the main character Linden doesn't have an answer yet. That one felt really validating for my kid who also had no clue. "Lola and the New School" by Keka Novales was perfect for my daughter right before she switched classrooms because it shows someone scared about making that change, and there is some mild mean behavior in it that opened up a good conversation about standing up for yourself. On the lighter side, "Sadiq and Hooyo's Drum" by Siman Nuurali has this sweet thing about a boy who wants to share his family heirloom with a deaf friend, and my daughter still mentions how cool it was that they found a way to communicate. We also grabbed "Biscuit's Graduation Day" by Alyssa Satin Capucilli right before her end of year program because it's about a little puppy getting in on the graduation action, and the short sentences made it easy for her to read most of it herself.
All of these fit the Accelerated Reader levels you'd expect for this age group, sitting around 2.5 to 4 which works really well for kids in kindergarten through third grade. Most of them earn you half a point or a full point, which might not sound like much but it adds up fast when you are powering through easy reads to build confidence. My kiddo gets excited seeing her points total tick up, and these books are short enough that she can finish one in a sitting or two, which feels like a win for a newly independent reader.
If your kid is the type who asks a million questions about everything and wants to know how stuff really works, the Magic School Bus book "Rocky Road Trip" is right up their alley because it turns a field trip into an adventure full of rocks and minerals. These are great for taking to the library first since they are popular and often in stock, and you can always ask your school librarian which ones they have multiple copies of for AR testing. Once your kid finds a character they like, they will probably hunt down every book in that series, which is honestly the best problem to have.