Using a binder with my third graders has been an excellent organizational tool. I've used one for the past several years, and it's helped me and the children, and the parents love it too! Here is what I put on my supply list:
a 1 1/2 inch white binder with clear-view plastic cover
a 3-hole zipper pouch
10 clear sheet protectors
3-hole plastic durable poly folder
On one of the first days of school, we build their "STAR Binder" and they get so excited about it! STAR stands for "Students That Are Responsible" and they are eager to show that they're responsible!!
We slide the STAR cover (part of the TpT bundle) into the clear view plastic cover of the binder, and we add in the other components.
The zipper pouch is for excuse cards, lunch money, and notes between parents and teacher. It isn't for pencils or other supplies :)
In addition to what I have the students supply, our school gives the students 3-hole homework books/agendas. We add those into our STAR binders as well. We also add in our reading logs, where the students keep track of their nightly reading.
I use the plastic sheet protectors for their STAR rules (also part of the TpT bundle), a copy of the class list and schedule, a "homework helpers" sleeve, with a copy of the word wall and a multiplication table and 100s chart, the current spelling list and contract, the current monthly book report, and any other key papers that I feel are helpful.
The students make one side of the folder say "Keep" and the other side "Return."
The students are required to take their STAR binder home every night and bring it back to school each day, with a parent signature in their agenda books to show that the parents have seen the papers and communications in the binder. The signature also serves as a way to show that the student has completed their homework and nightly reading.
I have included the STAR cover, rules sheet, and the contract in my TpT bundle for FREE!! The contract is just an agreement that I have the students sign and then I hold onto in case they ever need reminding of the rules they signed off on!